I am using Bower to install several libraries. For demonstration purposes here, I am installing bootstrap. Regardless of the package, I receive the following errors:
git config --global url. "https://".insteadOf "git://"
was not working for me. So I found this alternative:
Go to your temp folder. ( i.e. if you are using windows then C:\Users\{username}\AppData\Roaming\bower\cache\packages ). There you can see several files. Open each of them and you can see the URL. Change it from git://... to https://... and save all files.
Now run the bower install.