'Add an apt repository.
:param repo: Repository string. Example:
\'deb http://archive.ubuntu.com/ubuntu/ maverick universe\''

def add_repo(self, repo):

    repo_file = open(self.repo_file_path, 'a')
    repo_file_contents = repo_file.read()
    if (repo not in repo_file_contents):
        repo_file.write(repo)
