Dotenv-stripout

This patch ensures that commented lines in `.env` files are properly terminated with newlines in the stripped output

This fix handles lines in `.env` files which have been deliberately commented out, eg

.env
This is a comment
MY_SECRET_USERNAME=something-very-secret
MY_SECRET_PASSWORD=IqLTLrFviwHTDKWGZoR7uB2JtM1wjwE34MBwoztE


This would previously have appended an `=` to the comment:

.env
This is a comment=
MY_SECRET_USERNAME=
MY_SECRET_PASSWORD=


but will now be properly stripped as:

.env
This is a comment
MY_SECRET_USERNAME=
MY_SECRET_PASSWORD=

This fix allows `dotenv-stripout` to be installed alongside packages which require more recent versions of its dependencies.

initial release