WIP: Attempts to adjust for Singularity

A rough, working attempt at getting the workflow to start with
Singularity. Needs a bit of cleanup to streamline the process. Leaving
it here for now so it is stored and not forgotten.

Author: jakirkham

nanshe_ipython.ipynb

@@ -84,7 +84,11 @@
         "import os\n",
         "from psutil import cpu_count\n",
         "\n",
-        "cluster_kwargs = {}\n",
+        "cluster_kwargs = {\n",
+        "    \"preexec_commands\": (\n",
+        "        \"singularity exec ~/nanshe_nanshe_workflow_latest.img \\\\\",\n",
+        "    ),\n",
+        "}\n",
         "client_kwargs = {}\n",
         "adaptive_kwargs = {\n",
         "    \"minimum\": 0,\n",