Merge branch 'feature/option-at' into develop

* feature/option-at:
  fix option[:at]
  update readme
  make seconds option for option[:at]
  update readme
  update readme
  update readme for option[:at]
  add option[:at]
add rspec with some tests
refactor time parsing
add some more tests
add travis.yml for Travis CI
fix typo in travis.yml
add rake file for travis testing
Update README.md
Update README.md
Update README.md
add test coverage integration for codeclimate and travis ci
Merge branch 'develop' of github.com:sellect/delayed_cron into develop
update bundle
update repo token for travis ci / codeclimate integration