Enable a list of RHSM repositories.

        :param repositories: a dict in this format:
            [{'type': 'rhsm_channel', 'name': 'rhel-7-server-rpms'}]

def enable_repositories(self, repositories):
        """Enable a list of RHSM repositories.

        :param repositories: a dict in this format:
            [{'type': 'rhsm_channel', 'name': 'rhel-7-server-rpms'}]
        """
        for r in repositories:
            if r['type'] != 'rhsm_channel':
                continue
            if r['name'] not in self.rhsm_channels:
                self.rhsm_channels.append(r['name'])

        if self.rhsm_active:
            subscription_cmd = "subscription-manager repos '--disable=*' --enable=" + ' --enable='.join(
                self.rhsm_channels)
            self.run(subscription_cmd)

        repo_files = [r for r in repositories if r['type'] == 'yum_repo']
        for repo_file in repo_files:
            self.create_file(repo_file['dest'], repo_file['content'])

        packages = [r['name'] for r in repositories if r['type'] == 'package']
        if packages:
            self.yum_install(packages)