Update cylcache

[The9Cat]

Begin work for deprecation of cylcache

Turns out that we already had a script to make a basis using mpi4py. This PR does the following:

• Renames to create cylinder cache. We could call this cylcache, optionally
• Adds an option parser (argparse) which allows the user to get a YAML template and reads a YAML config
• Cleans up the MPI interface for printing help info, etc.
• Provides a simple example of running with mpirun in the help documentation

The routine and its options has been tested.

To Do

• Is the name okay?
• Do we need different options? I think that the YAML config should cover all the bases since all that's really happening is invoking the constructor.

[The9Cat]

Updated the create cylinder basis to work as an executable with optional YAML config file as input.

[The9Cat]

We could rename create cylinder basis to cylcache, if we think that would help...