feat: exclude the example app from code coverage (#297)

Instead of deleting the tests, we can just exclude this project from the reports

Author: smyrick

codecov.yml

@@ -0,0 +1,8 @@
+#
+# codecov.io Configuration
+# See the docs here: https://docs.codecov.io/docs/codecov-yaml
+#
+
+# Ingore the example app from coverage reports
+ignore:
+  - "graphql-kotlin-spring-example/**/*"