Fix CI builds (#286)

* update test app gems and fix more deprecation errors
* replace minitest with rspec for consistency. cleanup Rakefile

lib/generators/active_record/impressionist_generator.rb

@@ -15,7 +15,7 @@ module ActiveRecord
       end
 
       def create_migration_file
-        migration_template 'create_impressions_table.rb', 'db/migrate/create_impressions_table.rb'
+        migration_template 'create_impressions_table.rb.erb', 'db/migrate/create_impressions_table.rb'
       end
     end
   end

lib/generators/impressionist_generator.rb

@@ -5,7 +5,7 @@ module Impressionist
       source_root File.expand_path('../templates', __FILE__)
 
       def copy_config_file
-        template 'impression.rb', 'config/initializers/impression.rb'
+        template 'impression.rb.erb', 'config/initializers/impression.rb'
       end
 
     end