Please upgrade to 2.2 here.
The 2.0 and 2.1 branches are no longer being updated.
What's up with the Google Sign In?
I'm clicking Enable "Google Sign In" in my Manage Plugins section, but I'm getting the following error.
The addon could not be enabled because it generated a fatal error:
GoogleSignIn is missing the following requirement(s): OpenID 0.1a.
Why is this?