reduce tolerance in Bartman 2021 example to avoid timeout on Travis (+add TODO)

Author: slayoo

PySDM_examples/Bartman_et_al_2021/demo.ipynb

@@ -104,6 +104,8 @@
     "settings.n_steps = int(1.75 * settings.n_spin_up)\n",
     "settings.outfreq = int(1 * si.minute / settings.dt)\n",
     "settings.adaptive = True\n",
+    "settings.condensation_rtol_x = 1e-3  # TODO: needed to avoid timeout on Travis, revisit\n",
+    "settings.condensation_rtol_thd = 1e-3\n",
     "\n",
     "storage = Storage()\n",
     "simulation = Simulation(settings, storage)\n",
@@ -306,4 +308,4 @@
  },
  "nbformat": 4,
  "nbformat_minor": 4
-}
+}