Oauth2 Headshot URI
A new OAuth2 claim for the headshot URI was [just announced](https://devforum.roblox.com/t/public-beta-building-your-applications-with-oauth-20/2401354/173?u=treeben77). When authorizing OAuth2 with the `profile` scope, it can be accessed using `AccessToken.user.headshot_uri`.
Requests Sessions
All HTTP requests to Roblox in the library now use a request session object, which makes requests slightly faster.
Bug Fixes
- Fixed a bug which would make OAuth2 not work if both `jwt` and `PyJWT` were installed.