style: update codeclimate config to be less sensitive to duplicate code blocks

After conversing with Dave from CodeClimate, he suggested these changes to adjust CodeClimate's detection so that it does not alert as frequently for code blocks that are similar, but functionally different. I also added a line to enforce the rule of threes, since CC often alerted only when two blocks were identical.

.codeclimate.yml

@@ -17,6 +17,14 @@ checks:
   similar-code:
     config:
       threshold: 65
+plugins:
+  duplication:
+    enabled: true
+    config:
+      languages:
+        javascript:
+          mass_threshold: 110
+          count_threshold: 3
 exclude_paths:
 - "public/vendor/*"
 - "test/*"