Update or delete branches

[dmey]

@bss116 @samoliverowens @tomgrylls can you please start to bring your branches up-to-date with master when you have a moment to avoid merge conflicts later on when we update headers etc.

This can be done with the following command:

# From your branch
git fetch --all
git merge origin master

[samoliverowens]

Ok I've updated my so/diurnal-cycle branch - this is what I'm using to run simulations, and there are a few changes that should probably go into the master that I will create a PR for at some point (see issue #118).