Previously we were only updating group membership when a user record was
first created in an SSO setting.
This corrects it so we also update it if SSO changes the email
This change both speeds up specs (less strings to allocate) and helps catch
cases where methods in Discourse are mutating inputs.
Overall we will be migrating everything to use #frozen_string_literal: true
it will take a while, but this is the first and safest move in this direction
This updates tests to use latest rails 5 practice
and updates ALL dependencies that could be updated
Performance testing shows that performance has not regressed
if anything it is marginally faster now.
