Develop Snakefile on a node

We can start developing the Snakefile on a compute node (`srun --pty bash`) using 1 core, then when a user's Snakefile uses more than 1 core, the workflow manager will kill their session for grabbing more than was allocated. This becomes an HPC & shared resource lesson, and marks the turning point between live development of the script and launching it through the head node. Hat tip @tobyhodges 