Added unit test for class PpmFile.
Minor change: clean-up.
Minor change: clean-up.
Minor change: rewording.
Merge branch 'master' of github.com:TimBeattieEdUni/PS-Coursework-I
Added unit test for class Landscape - not yet working though.
Merge branch 'master' of github.com:TimBeattieEdUni/PS-Coursework-I