Always use https for W3C stylesheets and logo

See discussion at https://github.com/darobin/respec/commit/48a748ccb1caaa7d4ba42286e94ccb433e921d52
Update test
Merge pull request #242 from lanthaler/always-https

Always use https for W3C stylesheets and logo
v3.1.60
Merge branch 'release/v3.1.60' into develop
fixed merge conflict