Make sure node modules folder is not ignored
Make sure node modules folder is not ignored

Github pages was recently moved to jekyll 3.3 which ignores
"node_modules" and "vendors" directories, adding an empty ".nojekyll"
file will prevent those directories to be ignored.

Closes #2740

bitovi/canjs,bitovi/canjs,gsmeets/canjs,bitovi/canjs,gsmeets/canjs,bitovi/canjs,gsmeets/canjs