Add Bower ignores

Avoid consumers of the package getting unnecessary files installed in
their project.
Update `.bowerrc`

Bower now uses `bower.json` by default, so this configuration is not
necessary.

Bower will soon be switching the default installation directory to
`bower_components`, so explicitly telling it to use `components` will
protect against that future change.
Merge pull request #6 from necolas/fix/bower-config

Minor Bower configuration improvements