Issue
Your app uses Bower to install packages but in your build you see errors like Request to https://bower.herokuapp.com/packages/PACKAGE-NAME failed with 410
Resolution
You'll need to upgrade bower:
npm install -g bower
Alternatively you can put the following in your .bowerrc:
{
"registry": "https://registry.bower.io"
}
This was an undocumented change to bower:
https://github.com/bower/bower/issues/2484