add codecov config

Author: 2bndy5

codecov.yml

@@ -0,0 +1,11 @@
+coverage:
+  status:
+    patch:
+      default:
+        informational: true
+    project:
+      default:
+        target: auto
+        # adjust accordingly based on how flaky your tests are
+        # this allows a 2% drop from the previous base commit coverage
+        threshold: 2%