In docs generation use folium from folder
We should be able to create docs without having to install folium to the system. By inserting the path of the folder with folium in it in the system path `folium` can be imported without installation.
# All configuration values have a default; values that are commented out
# serve to show the default.
-import sys, os
+import sys
+import os
+
+# Use the currently checked out folium of this folder
+sys.path.insert(0, os.path.abspath(os.pardir))
# If extensions (or modules to document with autodoc) are in another directory,
# add these directories to sys.path here. If the directory is relative to the
