updated notebooks

Author: Bruno Goncalves

1. Pitfalls.ipynb

@@ -58,20 +58,20 @@
       "\n",
       "Compiler    : Clang 10.0.0 \n",
       "OS          : Darwin\n",
-      "Release     : 20.6.0\n",
+      "Release     : 21.4.0\n",
       "Machine     : x86_64\n",
       "Processor   : i386\n",
       "CPU cores   : 16\n",
       "Architecture: 64bit\n",
       "\n",
-      "Git hash: 1de312ab8ec83b204e8a22ebe02393243330f40f\n",
+      "Git hash: 15de955aafec6081e8f52615cf18b3f0d2b1136d\n",
       "\n",
-      "watermark      : 2.1.0\n",
+      "numpy          : 1.19.2\n",
       "matplotlib     : 3.3.2\n",
-      "numpy_financial: 1.0.0\n",
       "json           : 2.0.9\n",
-      "numpy          : 1.19.2\n",
+      "watermark      : 2.1.0\n",
       "pandas         : 1.1.3\n",
+      "numpy_financial: 1.0.0\n",
       "\n"
      ]
     }