Updated gem dependencies.
Convert specs to RSpec 3.0.0 syntax with Transpec

This conversion is done by Transpec 2.2.1 with the following command:
    transpec

* 1 conversion
    from: describe 'some helper' { }
      to: describe 'some helper', :type => :helper { }

* 1 conversion
    from: describe 'some model' { }
      to: describe 'some model', :type => :model { }

* 1 conversion
    from: describe 'some request' { }
      to: describe 'some request', :type => :request { }

For more details: https://github.com/yujinakayama/transpec#supported-conversions
Fixed bug with missing Active Model requirement and RSpec deprecation warnings.