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

		: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.

		: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
		"""
		# checkout the branch
		self.repo.create_head(branch, "refs/remotes/origin/%s" % branch)

		since_str = datetime.datetime.fromtimestamp(since).strftime('%Y-%m-%d %H:%M:%S')
		commits = {}
		for commit in self.repo.iter_commits(branch, since=since_str):
			# filter out all commits younger then to
			if commit.committed_date > to:
				continue

			commits[commit.hexsha] = self._commitData(commit)

		return commits