Add generated Rails app

This app was generated by:
`rails new . --skip-bundle --skip-test-unit --skip-javascript`

See https://github.com/gonzalo-bulnes/simple_token_authentication/\
    blob/fix-authentication-token-not-renewed-after-password-change/\
    features/step_definitions/dummy_app_steps.rb#L18
Add Simple Token Authentication, RSpec, Factory Girl
Setup RSpec with Factory Girl

See https://github.com/gonzalo-bulnes/simple_token_authentication/\
        blob/fix-authentication-token-not-renewed-after-password-change/\
        features/step_definitions/dummy_app_steps.rb#L32-L42
Add Travis