You tagged a release (1.3.0), but didn't update the version in component.json.
This makes bower complain when importing spin.js.
bower copying /Users/paul/.bower/cache/spin.js/3f476a1a66c4fd0dd527354578f4549c
mismatch The version specified in the component.json of package spin.js mismatches the tag (1.3.0 vs 1.2.8)
mismatch You should report this problem to the package author
Fixed. Thanks for reporting!