Adapt code to new pandas warnings

Author: uvchik

example/modelchain_example.ipynb

@@ -130,9 +130,9 @@
     "        'Europe/Berlin')\n",
     "    # change type of height from str to int by resetting columns\n",
     "    weather_df.columns = [weather_df.axes[1].levels[0][\n",
-    "                              weather_df.axes[1].labels[0]],\n",
+    "                              weather_df.axes[1].codes[0]],\n",
     "                          weather_df.axes[1].levels[1][\n",
-    "                              weather_df.axes[1].labels[1]].astype(int)]\n",
+    "                              weather_df.axes[1].codes[1]].astype(int)]\n",
     "    return weather_df\n",
     "\n",
     "\n",

example/modelchain_example.py

@@ -80,9 +80,9 @@ def get_weather_data(filename='weather.csv', **kwargs):
         'Europe/Berlin')
     # change type of height from str to int by resetting columns
     weather_df.columns = [weather_df.axes[1].levels[0][
-                              weather_df.axes[1].labels[0]],
+                              weather_df.axes[1].codes[0]],
                           weather_df.axes[1].levels[1][
-                              weather_df.axes[1].labels[1]].astype(int)]
+                              weather_df.axes[1].codes[1]].astype(int)]
     return weather_df