insert linkheader test

Change-Id: I57f3c5ed45d96f7e7e7ca22bb37f4dc2adedb5bd
Merge branch 'feature/tests' of ssh://gerrit.wikimedia.org:29418/mediawiki/extensions/PubSubHubbub into feature/tests
remove unused file

Change-Id: I9576640bcf9e088791efa06dc37673d089096636