MPHYG001 Research Software Engineering With Python coursework 1
http://development.rc.ucl.ac.uk/training/engineering/
usage: greengraph [-h] --from START --to END --steps STEPS [--out OUT]
Generates a graph of the proportion of green pixels in a series of satellite
images between two points
optional arguments:
-h, --help show this help message and exit
--from START Start city for Greengraph
--to END End city for Greengraph
--steps STEPS Number of images to process between the cities
--out OUT Destination file to save the graph. Graph is displayed if no
output specified.