Adds bash script which takes pictures from a connected webcam

The pictures are saved with the time and date they were taken. A possible
approach would be to set up a cron job to run this script every minute. The
instructions for the cron job are included in the bash script as a comment at
the bottom.
Re-organises work into Balloon and Ground Station

Should be easier to see which sub-project is linked to what as a result.
First draft of camera controller

Searches for images within a set directory which we've earmarked for the
camera to use. When the controller finds an image there, it returns the
path as the latest image to use. In a later commit, we'll create a
concrete camera data writer which does something with that image.
Updates CameraController to scan selected images dir for new files

When the controller is asked for its current data, it returns the paths
of any files in the images directory. In a future commit, I'll create a
writer which then moves those files into the storage directory for the
flight. Adds unit tests for the camera controller. I've updated the config
properties to work for my current env (Mac). At some point I'll update that
to be correct for the Raspberry Pi, and then I won't commit any more
changes to that path.
Adds camera file writer

Takes the file paths which were given to it by the camera sensor
controller and moves them into the storage directory.
Merge branch 'features/webcam'