Stop fetching `package.json` for bower, make `bower.json` optional
Fetch package.json for bower components, but ignore dependencies
Default to "0.0.0" version if bower.json contains no version

This is important, because bower is considering making the version
attribute in bower.json optional. But rave needs a version to be able
to correctly normalize package ids.
Add a comment about falling back to package.json
If no bower.json or package.json exists - fabricate the meta
Merge pull request #40 from KidkArolis/bower-no-more-package-json

Make bower crawler more robust