Use GitHub API keys to make GitHub API calls

[faokryn]

Currently, our requests to the GitHub API are rate limited.

Develop functionality to use the user's GitHub API key to make requests, thus removing the rate limiting.
Create a means by which users who are not logged into GitHub could be prompted to log in so that their key can be used.

[faokryn]

@sam1360 take a look at this when you get a chance and add anything else you think we need to do as part of this ticket