parsl provider for psi-j-python executors

A Parsl ExecutionProvider is very similar to a psi-j-python JobExecutor.

This package attempts to make JobExecutors usable as Parsl ExecutionProviders.

So far I've tested that the parsl test suite runs to completion without errors with the local and slurm executors.

Install

The current install is based around the development branches of various git repositories. To install the stack, do this:

git checkout https://github.com/parsl/parsl
cd parsl/
pip install .[psij]

This will install parsl, psi/j, and this psi-j-parsl package from github.