oauth using optional dependencies

Bug 1223524

Change-Id: Ic0d53fd1d5b3b7a587d33dc230e9ff200782ad4f
only run flake8 once (bug 1223023)

Change-Id: I0f492ad582fa7e609cccacd6d24f6c97bf731a85
Merge "oauth using optional dependencies"
Merge "only run flake8 once (bug 1223023)"