Merge pull request #2311 from alphagov/dependabot/bundler/gds-sso-21.1.0

Author: govuk-ci

Gemfile.lock

@@ -145,7 +145,7 @@ GEM
       plek (>= 1.9.0)
       rack (>= 2.2.0)
       rest-client (~> 2.0)
-    gds-sso (21.0.0)
+    gds-sso (21.1.0)
       oauth2 (~> 2.0)
       omniauth (~> 2.1)
       omniauth-oauth2 (~> 1.8)