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'
Removes out of date projects from ground station folder

The ground station code will be written in Javascript with Node. Getting
rid of old out of date code to make way for this.
Overhaul of how we write data from the balloon

We now have a better idea of how data will be sent between the balloon
and the ground station. We use the telemetryKeys json file as a common
schema for our data, hence why it has been moved up to the top level of
the repository. We now write data as a csv string. Every second, we
query the state of our sensors, and build up a data model based on that.
We then convert that model to a csv string using the data keys in the
schema.

Camera data is different from other data, so I no longer try and treat it
in the same way. As well as our other sensors, we now have a separate
camera sensor and data writer, with their own APIs.
Merge branch 'master' into features/mongodb