Revert nrealizations

Author: jtgrasb

examples/tutorial_4_Pioneer.ipynb

@@ -97,7 +97,7 @@
     "# irregular\n",
     "Hs = 1.5\n",
     "Tp = 5 \n",
-    "nrealizations = 1\n",
+    "nrealizations = 2\n",
     "\n",
     "fp = 1/Tp\n",
     "efth = pierson_moskowitz(freq=freq_irreg, hs=Hs, fp=fp)\n",