Added
- Added support to python 3.6.
- Added possibility to specify environments' configuration file location using `PYDOCKENV_CONF_FILE_DIR` env var.
- [internal] Added testing with python 3.6.
- [internal] Added some others integraion tests.
Changed
- [internal] Cleaned `.travis.yml`.
Fixed
- Fixed removal of key from environments configuration file when an environment is removed.
- Fixed update of environments configuration file that prevents some commands to work.