DomElementWrapper.get|setClassName were removed in 1.3.0

See https://github.com/ariatemplates/ariatemplates/commit/d49734f4d83ea239ca9c5b19f0a2db8dba3d39ff

Close #10
Merge pull request #10 from jakub-g/master

Seems legit to me, I am merging ! :shipit: