Added test json

Author: Nyholm

tests/webhook_examples/pull_request.opened_target_branch.header.txt

@@ -0,0 +1,8 @@
+Request URL: http://carson.knpuniversity.com/webhooks/github
+Request method: POST
+Accept: */*
+content-type: application/x-www-form-urlencoded
+User-Agent: GitHub-Hookshot/b1c41a3
+X-GitHub-Delivery: d9c13b80-17ae-11eb-8ab5-293f6833841d
+X-GitHub-Event: pull_request
+X-GitHub-Hook-ID: 141546673