added support for "licenses" => ["license"]

The error occured when trying to retrieve the license for
the npm module ember-template-compiler, which had the following license:

"licenses": [
    "MIT"
 ]
adding basic bower support

This solution is far from optimal, as it hardcodes the package manifest
location to `bower.json`.  Also, many people do not keep much
information in bower configs since they usually contain a `package.json`
in the same project.
Merge pull request #50 from CoffeeAndCode/licenses-with-string

added support for "licenses" => ["license"]
Merge pull request #51 from CoffeeAndCode/bower

adding basic bower support