Fix geoviews not working. (#103)

`gts.tile_sources['StamenLabels']` is deprecated (?), change to `gts.StamenLabels`.

Author: Holmgren825

oggm-edu/glacier_water_resources.ipynb

@@ -215,7 +215,7 @@
     "    sh = salem.transform_geopandas(gdir.read_shapefile('outlines'))\n",
     "    out = (gv.Polygons(sh).opts(fill_color=None, color_index=None) * \n",
     "           gts.tile_sources['EsriImagery'] * \n",
-    "           gts.tile_sources['StamenLabels']).opts(width=800, height=500, active_tools=['pan', 'wheel_zoom'])\n",
+    "           gts.StamenLabels).opts(width=800, height=500, active_tools=['pan', 'wheel_zoom'])\n",
     "except:\n",
     "    # The rest of the notebook works without this dependency\n",
     "    out = None\n",

oggm-edu/glacier_water_resources_projections.ipynb

@@ -185,7 +185,7 @@
     "    sh = salem.transform_geopandas(gdir.read_shapefile('outlines'))\n",
     "    out = (gv.Polygons(sh).opts(fill_color=None, color_index=None) * \n",
     "           gts.tile_sources['EsriImagery'] * \n",
-    "           gts.tile_sources['StamenLabels']).opts(width=800, height=500, active_tools=['pan', 'wheel_zoom'])\n",
+    "           gts.StamenLabels).opts(width=800, height=500, active_tools=['pan', 'wheel_zoom'])\n",
     "except:\n",
     "    # The rest of the notebook works without this dependency\n",
     "    out = None\n",
@@ -578,7 +578,7 @@
     "    sh = salem.transform_geopandas(gdirs[1].read_shapefile('outlines'))\n",
     "    out = (gv.Polygons(sh).opts(fill_color=None, color_index=None) * \n",
     "           gts.tile_sources['EsriImagery'] *\n",
-    "           gts.tile_sources['StamenLabels']).opts(width=800, height=500, active_tools=['pan', 'wheel_zoom'])\n",
+    "           gts.StamenLabels).opts(width=800, height=500, active_tools=['pan', 'wheel_zoom'])\n",
     "except:\n",
     "    # The rest of the notebook works without this dependency\n",
     "    out = None\n",