Fixed authenticator to use get_or_insert.
Fixed authenticator to use get_or_insert.

jordonwii/ok,jordonwii/ok,Cal-CS-61A-Staff/ok,Cal-CS-61A-Staff/ok,jackzhao-mj/ok,Cal-CS-61A-Staff/ok,Cal-CS-61A-Staff/ok,jackzhao-mj/ok,jordonwii/ok,jackzhao-mj/ok,Cal-CS-61A-Staff/ok,jordonwii/ok,jackzhao-mj/ok