CI: Add configuration for Codecov.io

Author: amotl

codecov.yml

@@ -0,0 +1,13 @@
+# https://docs.codecov.io/docs/common-recipe-list
+# https://docs.codecov.io/docs/commit-status#patch-status
+
+coverage:
+  status:
+
+    project:
+      default:
+        target: auto    # the required coverage value
+
+    patch:
+      default:
+        target: auto    # the required coverage value