For given branch return a list of commits.
		Each commit contains basic information about itself.

		Raises GithubException if rate limit is exceeded

		:param branch: git branch
		:type  branch: str
		:param since: minimal timestamp for commit's commit date
		:type  since: int
		:param to: maximal timestamp for commit's commit date
		:type  to: int

def commits(self, branch, since=0, to=int(time.time()) + 86400):
		"""For given branch return a list of commits.
		Each commit contains basic information about itself.

		Raises GithubException if rate limit is exceeded

		:param branch: git branch
		:type  branch: str
		:param since: minimal timestamp for commit's commit date
		:type  since: int
		:param to: maximal timestamp for commit's commit date
		:type  to: int
		"""
		if self.github.get_rate_limit().rate.limit == 0:
			raise GithubException

		commits = {}
		since_dt = datetime.datetime.fromtimestamp(since)
		to_dt = datetime.datetime.fromtimestamp(to)
		for commit in self.repo.get_commits(sha=branch, since=since_dt, until=to_dt):
			commits[commit.sha] = self._commitData(commit)
		return commits