Updated project to work with mapbox.

Installed django-geojson. Added geojson to requirements. Created url, view and template for map hosted from Mapbox.  Created  GeoJSONLayer urls for person and marker. Added Mapbox to map template and loaded markers with popups using mapbox.js. Update navigation bar in base template to include link to map template. Updated button in carousel with link to map template. Also updated test for two geojson urls and map url.
Altered case of secret key.
Merge pull request #17 from jzmiller1/map_fb

Initial implementation of cemetery web map.