Unreviewed. Add myself as a committer. Yoo-hoo! \o/

* Scripts/webkitpy/common/config/contributors.json:

git-svn-id: http://svn.webkit.org/repository/webkit/trunk@153584 268f45cc-cd09-0410-ab3c-d52691b4dbfc
http/tests/multipart/invalid-image-data-standalone.html needs to skipped, not
just marked as failing, otherwise it gets listed as a test that times out.

* platform/mac/TestExpectations:

git-svn-id: http://svn.webkit.org/repository/webkit/trunk@153585 268f45cc-cd09-0410-ab3c-d52691b4dbfc