Make tests slightly less specific so that they don't clash on filenames
Add audio app to separate out transcoding of audio files
Move TranscribeHelper and TranscribeException into util module
Use transcribe util classes from util module and tidy imports
Refactor starting off transcribing to a method on the Speech model, so that helpers can all live in speeches.util happily by themselves
Rename speeches.util to .utils, to match django naming conventions
Refactor audio conversion into separate helper class and test it on it's own
Remove audiomodule, that was unneccessary