remove minified source from bower.json main

main section should not include minified sources:
https://docs.google.com/document/d/1APq7oA9tNao1UYWyOm8dKqlRP2blVkROYLZ2fLIjtWc/edit#heading=h.jmmgkr9iuyac
Merge pull request #594 from joernhees/patch-1

remove minified source from bower.json main