Add support for username:password pairs

[sygibson]

This Pull adds support to specify username:password for authentication.

If only username is specified (eg no :password), then the interactive dialog will be called as per the original usage.

The password can be usernames Github account password, or a Github Access Token, which is documented at: https://help.github.com/articles/creating-a-personal-access-token-for-the-command-line/

[nchah]

Hi Shane! Thank you for the pull request and for updating the documentation! This should be merged soon.

I realize this may be an edge case, but GitHub also accepts "spaces" in passwords. With that in mind, perhaps it's better to remove the ".strip" call from line 232 and 238? Hi Shane! Thank you for the pull request and for updating the documentation! This should be merged soon.

I realize this may be an edge case, but GitHub also accepts "spaces" in passwords. With that in mind, perhaps it's better to remove the ".strip" call from line 232 and 238?

[sygibson]

That's a good question. I've seen a lot of auto-complete form responses in browsers inject a trailing space, assuming another word is next. That is the use case I was thinking of with the .strip call. You're right that it might interfere with input if the user has a legitimate space on the beginning or end of the user/pass pair.

[nchah]

Thanks for the explanation! I am also a fan of sanitizing for spaces. If users have trailing/leading spaces in their password, they could always input it themselves under the usual input method (i.e. $ python main.py 'nchah' '[repo...]') or someone may file an issue/PR in the future as needed.

[AnthonyBloomer]

Nice contribution Shane. I'll get this pushed to PyPi at some stage today.