Fix indentation

Author: AustinRochford

pymc3/examples/dp_mix.ipynb

@@ -22,13 +22,13 @@
     "    \n",
     " where $\\delta$ is the [Dirac delta measure](https://en.wikipedia.org/wiki/Dirac_delta_function)\n",
     " \n",
-    "    $$\\begin{align*}\n",
-    "        \\delta_{\\omega}(S)\n",
-    "            & = \\begin{cases}\n",
-    "                    1 & \\textrm{if } \\omega \\in S \\\\\n",
-    "                    0 & \\textrm{if } \\omega \\not \\in S\n",
-    "                \\end{cases}\n",
-    "    \\end{align*}.$$\n",
+    " $$\\begin{align*}\n",
+    "     \\delta_{\\omega}(S)\n",
+    "         & = \\begin{cases}\n",
+    "                 1 & \\textrm{if } \\omega \\in S \\\\\n",
+    "                 0 & \\textrm{if } \\omega \\not \\in S\n",
+    "             \\end{cases}\n",
+    " \\end{align*}.$$\n",
     "\n",
     "2. The posterior predictive distribution of a new observation is a compromise between the base measure and the observations,\n",
     "\n",