Use the new develop WordPress repo for testing

Signed-off-by: Paul de Wouters <paul@hmn.md>
Change bootstrap

Signed-off-by: Paul de Wouters <paul@hmn.md>
fix plugin path for tests

Signed-off-by: Paul de Wouters <paul@hmn.md>
update paths

Signed-off-by: Paul de Wouters <paul@hmn.md>
Merge branch 'update-travis-tests' into adds-grunt-tasks

Signed-off-by: Paul de Wouters <paul@hmn.md>

Conflicts:
	tests/bootstrap.php