Move Timber class check to the top of the file
Move Timber class check to the top of the file

The check is supossed to happen before the attempt to use. Also this
way the error message displays as it should.

stevesunderland/orourke-theme,studiorabota/sage-twig-theme,stevesunderland/orourke-theme,stevesunderland/orourke-theme,studiorabota/sage-twig-theme,studiorabota/sage-twig-theme