TestUser: Removed dead code

Refs: 895aa5f0d0aba97793fc5d41956e00338e5c4152
Fixed TestAuthenticateHandler

Added mock for AuthenticateHandler._fetch_google_userinfo
Refs: 895aa5f0d0aba97793fc5d41956e00338e5c4152
Fixed NextJobHandler

Get data via Redis bucket instead of MySQL DB.
Release 0.15.1
Fix materialgirl release requirement
Draft another release, 0.15.2