Slightly fix bower config

*  Use '>=' syntax for dependency (see https://github.com/isaacs/node-semver/)
*  Use non-minified files for the "main" keyword (see https://docs.google.com/document/d/1APq7oA9tNao1UYWyOm8dKqlRP2blVkROYLZ2fLIjtWc/edit#heading=h.jmmgkr9iuyac)