Log Message:
py-dotenv: updated to 0.15.0

0.15.0:

Added
- Add `--export` option to `set` to make it prepend the binding with `export`

Changed
- Make `set` command create the `.env` file in the current directory if no \ 
`.env` file was
  found.

Fixed
- Fix potentially empty expanded value for duplicate key.
- Fix import error on Python 3.5.0 and 3.5.1.
- Fix parsing of unquoted values containing several adjacent space or tab characters