feat: add fastapi integration

[iloveitaly]

extracted from: https://github.com/iloveitaly/python-starter-template/

[greptile-apps]

Greptile encountered an error while reviewing this PR. Please reach out to [email protected] for assistance.

[rafaeelaudibert]

We've updated our release process. We require sampo now. Please rebase on master and check README to understand what should be done.

[marandaneto]

@dustinbyrne have you ever used fastapi? we prob need a sampe app here https://github.com/PostHog/posthog-python/tree/master/examples so we can test this out

[dustinbyrne]

@iloveitaly this would be easier to review and merge if it had tests or an example as @marandaneto mentioned above. How would you like to proceed here? I'm happy to help out if you've moved on from this.

[marandaneto]

@dustinbyrne we can prob test this once #279 gets merged

[marandaneto]

@dustinbyrne we can prob test this once #279 gets merged

@iloveitaly since #470 got merged, can you make sure this works using that example? adding a test button/case etc