getCommit method
Fetches a commit from slug for a given sha.
API docs: https://developer.github.com/v3/git/commits/#get-a-commit
Implementation
Future<GitCommit> getCommit(RepositorySlug slug, String? sha) =>
github.getJSON(
'/repos/${slug.fullName}/git/commits/$sha',
convert: GitCommit.fromJson,
statusCode: StatusCodes.OK,
);