Behave like AR does wrt migrating dev and test storages

This change makes some rake tasks behave like so:

  rake db:create      # both dev and test repos
  rake db:drop        # only the current env repo
  rake db:automigrate # only the current env repo
  rake db:autoupgrade # only the current env repo
  rake db:migrate     # only the current env repo

Previously, db:drop/automigrate/autoupgrade were
operating on both dev and test repos if RAILS_ENV
was set to development.

While creating both dev and test repos when no
RAILS_ENV is specified (defaults to development)
makes sense, it doesn't make sense to perform the
other operations on both repo envs too.

[#1326 state:resolved]

lib/dm-rails/railties/database.rake

@@ -35,9 +35,6 @@ namespace :db do
   desc "Drops the database(s) for the current Rails.env - also drops the test database(s) if Rails.env.development?"
   task :drop => :environment do
     Rails::DataMapper.storage.drop_environment(Rails::DataMapper.configuration.repositories[Rails.env])
-    if Rails.env.development? && Rails::DataMapper.configuration.repositories['test']
-      Rails::DataMapper.storage.drop_environment(Rails::DataMapper.configuration.repositories['test'])
-    end
   end
 
 
@@ -48,13 +45,6 @@ namespace :db do
       ::DataMapper.auto_migrate!(repository.to_sym)
       ::DataMapper.logger.info "[datamapper] Finished auto_migrate! for :#{repository} repository '#{config['database']}'"
     end
-    if Rails.env.development? && Rails::DataMapper.configuration.repositories['test']
-      Rails::DataMapper.setup('test')
-      Rails::DataMapper.configuration.repositories['test'].each do |repository, config|
-        ::DataMapper.auto_migrate!(repository.to_sym)
-        ::DataMapper.logger.info "[datamapper] Finished auto_migrate! for :#{repository} repository '#{config['database']}'"
-      end
-    end
   end
 
   desc 'Perform non destructive automigration of all repositories in the current Rails.env'
@@ -64,13 +54,6 @@ namespace :db do
       ::DataMapper.auto_upgrade!(repository.to_sym)
       ::DataMapper.logger.info "[datamapper] Finished auto_upgrade! for :#{repository} repository '#{config['database']}'"
     end
-    if Rails.env.development? && Rails::DataMapper.configuration.repositories['test']
-      Rails::DataMapper.setup('test')
-      Rails::DataMapper.configuration.repositories['test'].each do |repository, config|
-        ::DataMapper.auto_upgrade!(repository.to_sym)
-        ::DataMapper.logger.info "[datamapper] Finished auto_upgrade! for :#{repository} repository '#{config['database']}'"
-      end
-    end
   end
 
   desc 'Load the seed data from db/seeds.rb'