Completely remove codeclimate as well

Most of it is already disabled, and the stuff that's not actually
disabled don't seem worth enough for me to keep it.

.codeclimate.yml

@@ -1,33 +0,0 @@
-version: "2"
-plugins:
-  duplication:
-    enabled: true
-    exclude_patterns:
-    - "db/**"
-    - "config/initializers/active_record_postgresql_referential_integrity_patch.rb"
-checks:
-  argument-count:
-    enabled: false
-  complex-logic:
-    enabled: false
-  file-lines:
-    enabled: false
-  method-complexity:
-    enabled: false
-  method-count:
-    enabled: false
-  method-lines:
-    enabled: false
-  nested-control-flow:
-    enabled: false
-  return-statements:
-    enabled: false
-  similar-code:
-    enabled: false
-  identical-code:
-    enabled: false
-exclude_patterns:
-- "spec/**/*"
-- "vendor/**/*"
-- "app/assets/javascripts/shared/*"
-- "app/assets/javascripts/jquery-migrate-1.0.0.js"