我在heroku上有一个应用程序。我已经清理了数据库（手动）。没有桌子。
现在我在运行 rails 环境时遇到问题。准确地说：问题是没有users桌子。运行需要环境rake db:migrate。所以我不能在数据库中创建模式。
这是日志：
/app/vendor/bundle/ruby/2.0.0/gems/activerecord-4.0.0/lib/active_record/connection_adapters/postgresql_adapter.rb:768:in `exec': PG::Error: ERROR: relation "users" does not exist (ActiveRecord::StatementInvalid)
LINE 5: WHERE a.attrelid = '"users"'::regclass
^
: SELECT a.attname, format_type(a.atttypid, a.atttypmod),
pg_get_expr(d.adbin, d.adrelid), a.attnotnull, a.atttypid, a.atttypmod
FROM pg_attribute a LEFT JOIN pg_attrdef d
ON a.attrelid = d.adrelid AND a.attnum = d.adnum
WHERE a.attrelid = '"users"'::regclass
AND a.attnum > 0 AND NOT a.attisdropped
ORDER BY a.attnum
from /app/vendor/bundle/ruby/2.0.0/gems/activerecord-4.0.0/lib/active_record/connection_adapters/postgresql_adapter.rb:768:in `exec_no_cache'
from /app/vendor/bundle/ruby/2.0.0/gems/activerecord-4.0.0/lib/active_record/connection_adapters/postgresql/database_statements.rb:138:in `block in exec_query'
from /app/vendor/bundle/ruby/2.0.0/gems/activerecord-4.0.0/lib/active_record/connection_adapters/abstract_adapter.rb:425:in `block in log'
from /app/vendor/bundle/ruby/2.0.0/gems/activesupport-4.0.0/lib/active_support/notifications/instrumenter.rb:20:in `instrument'
from /app/vendor/bundle/ruby/2.0.0/gems/activerecord-4.0.0/lib/active_record/connection_adapters/abstract_adapter.rb:420:in `log'
from /app/vendor/bundle/ruby/2.0.0/gems/activerecord-4.0.0/lib/active_record/connection_adapters/postgresql/database_statements.rb:137:in `exec_query'
from /app/vendor/bundle/ruby/2.0.0/gems/activerecord-4.0.0/lib/active_record/connection_adapters/postgresql_adapter.rb:915:in `column_definitions'
from /app/vendor/bundle/ruby/2.0.0/gems/activerecord-4.0.0/lib/active_record/connection_adapters/postgresql/schema_statements.rb:174:in `columns'
from /app/vendor/bundle/ruby/2.0.0/gems/activerecord-4.0.0/lib/active_record/connection_adapters/schema_cache.rb:114:in `block in prepare_default_proc'
from /app/vendor/bundle/ruby/2.0.0/gems/activerecord-4.0.0/lib/active_record/connection_adapters/schema_cache.rb:56:in `yield'
from /app/vendor/bundle/ruby/2.0.0/gems/activerecord-4.0.0/lib/active_record/connection_adapters/schema_cache.rb:56:in `columns'
from /app/vendor/bundle/ruby/2.0.0/gems/activerecord-4.0.0/lib/active_record/model_schema.rb:208:in `columns'
from /app/vendor/bundle/ruby/2.0.0/gems/activerecord-4.0.0/lib/active_record/model_schema.rb:253:in `content_columns'
from /app/vendor/bundle/ruby/2.0.0/gems/acts_as_relation-1.0.0/lib/active_record/acts_as_relation.rb:70:in `block (2 levels) in acts_as'
from /app/vendor/bundle/ruby/2.0.0/gems/acts_as_relation-1.0.0/lib/active_record/acts_as_relation.rb:112:in `include'
from /app/vendor/bundle/ruby/2.0.0/gems/acts_as_relation-1.0.0/lib/active_record/acts_as_relation.rb:112:in `block in acts_as'
from /app/vendor/bundle/ruby/2.0.0/gems/acts_as_relation-1.0.0/lib/active_record/acts_as_relation.rb:111:in `class_eval'
from /app/vendor/bundle/ruby/2.0.0/gems/acts_as_relation-1.0.0/lib/active_record/acts_as_relation.rb:111:in `acts_as'
from /app/app/models/admin.rb:2:in `<class:Admin>'
from /app/app/models/admin.rb:1:in `<top (required)>'
from /app/vendor/bundle/ruby/2.0.0/gems/activesupport-4.0.0/lib/active_support/dependencies.rb:228:in `require'
from /app/vendor/bundle/ruby/2.0.0/gems/activesupport-4.0.0/lib/active_support/dependencies.rb:228:in `block in require'
from /app/vendor/bundle/ruby/2.0.0/gems/activesupport-4.0.0/lib/active_support/dependencies.rb:213:in `load_dependency'
from /app/vendor/bundle/ruby/2.0.0/gems/activesupport-4.0.0/lib/active_support/dependencies.rb:228:in `require'
from /app/vendor/bundle/ruby/2.0.0/gems/activesupport-4.0.0/lib/active_support/dependencies.rb:329:in `require_or_load'
from /app/vendor/bundle/ruby/2.0.0/gems/activesupport-4.0.0/lib/active_support/dependencies.rb:462:in `load_missing_constant'
from /app/vendor/bundle/ruby/2.0.0/gems/activesupport-4.0.0/lib/active_support/dependencies.rb:183:in `const_missing'
from /app/app/controllers/admin/abstract_admin_controller.rb:1:in `<top (required)>'
from /app/vendor/bundle/ruby/2.0.0/gems/activesupport-4.0.0/lib/active_support/dependencies.rb:228:in `require'
from /app/vendor/bundle/ruby/2.0.0/gems/activesupport-4.0.0/lib/active_support/dependencies.rb:228:in `block in require'
from /app/vendor/bundle/ruby/2.0.0/gems/activesupport-4.0.0/lib/active_support/dependencies.rb:213:in `load_dependency'
from /app/vendor/bundle/ruby/2.0.0/gems/activesupport-4.0.0/lib/active_support/dependencies.rb:228:in `require'
from /app/vendor/bundle/ruby/2.0.0/gems/activesupport-4.0.0/lib/active_support/dependencies.rb:329:in `require_or_load'
from /app/vendor/bundle/ruby/2.0.0/gems/activesupport-4.0.0/lib/active_support/dependencies.rb:288:in `depend_on'
from /app/vendor/bundle/ruby/2.0.0/gems/activesupport-4.0.0/lib/active_support/dependencies.rb:206:in `require_dependency'
from /app/vendor/bundle/ruby/2.0.0/gems/railties-4.0.0/lib/rails/engine.rb:465:in `block (2 levels) in eager_load!'
from /app/vendor/bundle/ruby/2.0.0/gems/railties-4.0.0/lib/rails/engine.rb:464:in `each'
from /app/vendor/bundle/ruby/2.0.0/gems/railties-4.0.0/lib/rails/engine.rb:464:in `block in eager_load!'
from /app/vendor/bundle/ruby/2.0.0/gems/railties-4.0.0/lib/rails/engine.rb:462:in `each'
from /app/vendor/bundle/ruby/2.0.0/gems/railties-4.0.0/lib/rails/engine.rb:462:in `eager_load!'
from /app/vendor/bundle/ruby/2.0.0/gems/railties-4.0.0/lib/rails/engine.rb:347:in `eager_load!'
from /app/vendor/bundle/ruby/2.0.0/gems/railties-4.0.0/lib/rails/application/finisher.rb:56:in `each'
from /app/vendor/bundle/ruby/2.0.0/gems/railties-4.0.0/lib/rails/application/finisher.rb:56:in `block in <module:Finisher>'
from /app/vendor/bundle/ruby/2.0.0/gems/railties-4.0.0/lib/rails/initializable.rb:30:in `instance_exec'
from /app/vendor/bundle/ruby/2.0.0/gems/railties-4.0.0/lib/rails/initializable.rb:30:in `run'
from /app/vendor/bundle/ruby/2.0.0/gems/railties-4.0.0/lib/rails/initializable.rb:55:in `block in run_initializers'
from /app/vendor/ruby-2.0.0/lib/ruby/2.0.0/tsort.rb:150:in `block in tsort_each'
from /app/vendor/ruby-2.0.0/lib/ruby/2.0.0/tsort.rb:183:in `block (2 levels) in each_strongly_connected_component'
from /app/vendor/ruby-2.0.0/lib/ruby/2.0.0/tsort.rb:219:in `each_strongly_connected_component_from'
from /app/vendor/ruby-2.0.0/lib/ruby/2.0.0/tsort.rb:182:in `block in each_strongly_connected_component'
from /app/vendor/ruby-2.0.0/lib/ruby/2.0.0/tsort.rb:180:in `each'
from /app/vendor/ruby-2.0.0/lib/ruby/2.0.0/tsort.rb:180:in `each_strongly_connected_component'
from /app/vendor/ruby-2.0.0/lib/ruby/2.0.0/tsort.rb:148:in `tsort_each'
from /app/vendor/bundle/ruby/2.0.0/gems/railties-4.0.0/lib/rails/initializable.rb:54:in `run_initializers'
from /app/vendor/bundle/ruby/2.0.0/gems/railties-4.0.0/lib/rails/application.rb:215:in `initialize!'
from /app/vendor/bundle/ruby/2.0.0/gems/railties-4.0.0/lib/rails/railtie/configurable.rb:30:in `method_missing'
from /app/config/environment.rb:5:in `<top (required)>'
from /app/vendor/bundle/ruby/2.0.0/gems/activesupport-4.0.0/lib/active_support/dependencies.rb:228:in `require'
from /app/vendor/bundle/ruby/2.0.0/gems/activesupport-4.0.0/lib/active_support/dependencies.rb:228:in `block in require'
from /app/vendor/bundle/ruby/2.0.0/gems/activesupport-4.0.0/lib/active_support/dependencies.rb:213:in `load_dependency'
from /app/vendor/bundle/ruby/2.0.0/gems/activesupport-4.0.0/lib/active_support/dependencies.rb:228:in `require'
from /app/vendor/bundle/ruby/2.0.0/gems/railties-4.0.0/lib/rails/application.rb:189:in `require_environment!'
from /app/vendor/bundle/ruby/2.0.0/gems/railties-4.0.0/lib/rails/commands.rb:63:in `<top (required)>'
from /app/bin/rails:4:in `require'
from /app/bin/rails:4:in `<main>
这是管理员模型：
class Admin < ActiveRecord::Base
acts_as :user
strip_attributes
end
和用户模型：
class User < ActiveRecord::Base
acts_as_superclass
authenticates_with_sorcery!
validates :login, :email, presence: true
validates :login, format: { with: /\A[0-9a-z._-]{3,}\z/}
validates :login, uniqueness: { case_sensitive: false }
validates :email, format: { with: /\A([a-z0-9._%+-]+)@((?:[-a-z0-9]+\.)+[a-z]{2,})\z/i }
validates :password, length: { minimum: 3 }, :if => :password
validates :password, confirmation: true, :if => :password
strip_attributes except: [:password, :password_confirmation]
end
上面列出的模型（我想）是崩溃的原因。act_as_relation也许还有宝石。
有谁知道到底出了什么问题？以及如何解决？
PS 有趣的事情：我在本地计算机上复制了这个并且迁移工作正常！rails环境没有问题。我使用开发数据库，所以这可能会有所不同。