Allow users to push to GitHub#

We use gh-scoped-creds to allow users to safely push to GitHub from their JupyterHub. This requires a little setup on the hub side to make the user experience seamless.

Create a GitHub app under the 2i2c organization with the settings outlined in the gh-scoped-creds docs
Set environment variables gh-scoped-creds needs to figure out which GitHub app to use in the appropriate .values.yaml file for the hub in question.
```
 jupyterhub:
   singleuser:
      extraEnv:
         GH_SCOPED_CREDS_CLIENT_ID: <client-id-of-the-github-app>
         GH_SCOPED_CREDS_APP_URL: <public-url-of-the-github-app>
```
Note

If the hub is a daskhub, nest the config under a basehub key

Get this change deployed!
Make sure the gh-scoped-creds python package is available inside the user image.

This blog post provides more details on how users on the JupyterHub can use gh-scoped-creds to push changes to GitHub!