Determines the hosting service of `repo_url`.
    :param repo_url: Repo URL of unknown type.
    :returns: Hosting service or raises UnknownHostingService exception.

def identify_hosting_service(repo_url, hosting_services=HOSTING_SERVICES):
    """
    Determines the hosting service of `repo_url`.
    :param repo_url: Repo URL of unknown type.
    :returns: Hosting service or raises UnknownHostingService exception.
    """
    repo_url = unicode(repo_url)

    for service in hosting_services:
        if service in repo_url:
            return service

    raise UnknownHostingService