Issue title: [jss] font-face rule should not be of type "regular"
 Issue body: Related  to jss-isolate
 Comments: 
 Comment 0: b2f530d63c2cf502814c311cf258b4390ef2fcf7
 Comment 1: cc @maximkoretskiy
{'source': 'GithubIssues', 'repo_name_with_owner': 'jsstyles/jss', 'issue_id': 145647001, 'repo_stars': 1145.0}