Move model

SimpleCell.ipynb

@@ -18,6 +18,7 @@
     "import sys\n",
     "from tqdm import trange\n",
     "sys.path.insert(0, './Persistent_Homology')\n",
+    "sys.path.insert(0, './model')\n",
     "\n",
     "from gratings import grating_model, GRATING_PARS, get_locations\n",
     "import gratings\n",