Enabled

Hey Dylan we really liked your fork of the TestFlight plugin since we also add our own buildnotes to testflight uploads. When we added a slave jenkins machine, the plugin would always pick up the buildnotes from the master. Rather than copy the notes from the slave to the master, we decided to fix up the plugin to be able to get the notes from the slave. 

Getting the buildnotes file needs to be done in TestFlightUploader, since that is called by the RemoteRecorder, which is what allows code to run on a slave machine