Remove flay and flog

* The ruby parser they use does not support 2.5 syntax in full so we get
  lots of flip flop values when triggering or untriggering blindness in
  these tools.
* This noise reduces their value significantly.

.circleci/config.yml

@@ -35,8 +35,6 @@ jobs:
       - run: bundle install
       - run: bundle exec rake metrics:rubocop
       - run: bundle exec rake metrics:reek
-      - run: bundle exec rake metrics:flay
-      - run: bundle exec rake metrics:flog
   mutant:
     <<: *defaults
     steps:

config/flay.yml

@@ -1,3 +0,0 @@
----
-threshold: 16
-total_score: 1395

config/flog.yml

@@ -1,2 +0,0 @@
----
-threshold: 27.7