Fix bugs in splitting and add basic tests for splitting audio with 0, 1 and 2 timestamps in a recording
Move test fixture sound files into a better directory structure
Put mp3 files in the right folder
Refactor audio helper tests to use new fixture locations
Refactor tests to match new fixtures locations
Add a utc method to RecordingTimestamp so that we can get it as a UTC long without jumping through calendar hoops everytime
Finish split_recording method and unit tests for the AudioHelper class, including many new test fixture mp3s