The `audiotospectrogram` module is a complete rewrite of the existing spectrogram
code with support for Python 3. This allows us to drop the bundled `freesound`
library and Python 2-only `audioprocessing` and `spectrogram` modules.
Signed-off-by: Ben Sturmfels <ben@sturm.com.au>
Mostly a thorough test and cleanup. The significant change is moving the systemd
config into the deployment docs an the registration/security considerations to
production considerations docs.
