Figure out how to create a Gist

[cheshire137]

Gist API: https://developer.github.com/v3/gists/

We could:

• Handle authentication and Gist creation in the background with the plugin.
• Just cause the user's browser to open to the Gist creation page and paste in the copied text for them.

[cheshire137]

Fixed with https://github.com/LexLadiesCode/SublimeTextGistPlugin/commit/cc955a0980a57241e04fe25ef1952e33ad883b75