Add which branchs should be build by travis.
Merge branch 'develop' of github.com:globocom/pymigration into develop

* 'develop' of github.com:globocom/pymigration:
  Created requirements.txt
Created test-requirements
Add elasticsearch service to travis.
Merge branch 'develop' of https://github.com/globocom/pymigration into develop
Merge branch 'develop' of github.com:globocom/pymigration into develop

* 'develop' of github.com:globocom/pymigration:
  Created test-requirements
Add travis status do README.
Merge branch 'feature/commands' into develop
Merge branch 'develop' of github.com:globocom/pymigration into develop