Checks git context author

[jsegaran]

Description

Git contains an author and committer. The author is more semantically meaningful for what we are trying to show in studio.
We should send the git author instead of the committer to studio. Note the gql api is still called committer but we should rename it to author.

For github squash and merges the committer is set to no-reply@github.com instead of the email of the user which is stored in author so this makes post-merge attributions hard.