Add codecov.yml for coverage tracking

codecov.yml

@@ -0,0 +1,20 @@
+codecov:
+  require_ci_to_pass: true
+
+coverage:
+  precision: 2
+  round: down
+  range: "70...100"
+  status:
+    project:
+      default:
+        target: 70%
+        threshold: 1%
+    patch:
+      default:
+        target: 70%
+
+comment:
+  layout: "reach,diff,flags,files"
+  behavior: default
+  require_changes: false