Update tutorial.rst

Fix a typo that was causing readthedocs to not display the sample code for custom maps, at the end of the tutorial.

Author: davidwagner

docs/tutorial.rst

@@ -403,6 +403,7 @@ The main class in the maps module is the Map class. In this code we create a def
 The maps modules also allows you to make custom maps with markers, circles and regions.
 
 .. ipython:: python
+
     from datascience.maps import Map, Marker, Circle, Region            # import the Map, Marker, Circle and Region class
     
     # generates markers with custom sets of coordinates, colors and popups