fix(katib): Increase experiment batch-size (#93)

Increase experiment's batch-size in order for the experiment to perform 
less training and thus complete earlier. The UAT's role is to confirm that 
the controller works, rather than run a full experiment training.

Fixes canonical/katib-operators#211

tests/notebooks/katib/katib-integration.ipynb

@@ -172,7 +172,7 @@
     "                            \"python3\",\n",
     "                            \"/opt/pytorch-mnist/mnist.py\",\n",
     "                            \"--epochs=1\",\n",
-    "                            \"--batch-size=64\",\n",
+    "                            \"--batch-size=16384\",\n",
     "                            \"--lr=${trialParameters.learningRate}\",\n",
     "                            \"--momentum=${trialParameters.momentum}\",\n",
     "                        ]\n",