chore: add .codeclimate.yml

Don't be too harsh on PRs.
Breaking these rules gonna make PR marked as failure.

.codeclimate.yml

@@ -0,0 +1,11 @@
+version: "2"
+checks:
+  method-complexity:
+    config:
+      threshold: 8
+  method-lines:
+    config:
+      threshold: 100
+  file-lines:
+    config:
+      threshold: 500