Added the uploaded_media/ directory to the .gitignore

This is so that we don't start committing traces, and potentially any other uploaded media
to git.
If trace upload fails, the error is now printed to the stdout

This allows me to log the errors.
Traces are now stored on the controlserver

The api view has now been written that allows for traces to be uploaded and stored on the server.
Currently there is no concept of a run, and no frontend view to allow for utilising them.
They can currently be accessed in the directory /media/traces/ via HTTP