Upgrade CodeClimate config to a newer version

Author: pkuczynski

.codeclimate.yml

@@ -1,4 +1,5 @@
-engines:
+version: 2
+plugins:
   duplication:
     enabled: true
     config:
@@ -15,12 +16,5 @@ engines:
     enabled: true
   rubocop:
     enabled: true
-
-ratings:
-   paths:
-   - Gemfile.lock
-   - "**.md"
-   - "**.rb"
-
-exclude_paths:
-- "spec/app/**/*"
+exclude_patterns:
+  - "spec/"