Allow for using an API key instead of username/password combination

[IQAndreas]

Even though the script doesn't do anything "funny" with the user's credentials (which can be clearly seen since the code is open source) it's still not a good idea requiring a password in the script (and it's especially not a good idea to store that password in a plaintext file on your computer!)

I added the option of prompting for a password when the script, but I still would like the capability to use API keys instead.

[ntalbott]

This actually already works; if you create a Personal Access Token here:

You can then change config.ini like this:

[login]
username = <GENERATED TOKEN>
password = x-oauth-basic

Just used it and it worked like a charm.

[asmeurer]

This can also be done programmatically using the API.

[mikemaccana]

Added to README https://github.com/IQAndreas/github-issues-import/pull/75