Add data for number of children vaccinated

OpenNepal has [health data on number of children vaccinated](http://data.opennepal.net/content/district-wise-vaccinated-number-children-and-women-2009-10-2013-14). Take the data for 2013-2014 and, in the health section of NepalMap, show the number of children vaccinated by district for each of the vaccinations that are recorded. Here is a CSV (in txt format because that's what GitHub allows) extracted from that data.

[immunizations-2013.txt](https://github.com/Code4Nepal/nepalmap_app/files/1373886/immunizations-2013.txt)

Things to note:

- There is a health section in NepalMap. [Here it is at the country level](https://www.nepalmap.org/profiles/country-NP-nepal/#health). These data should be included in this section.
- National totals can be created by summing up the district-level numbers.
- Each immunization should be its own statistic. Please feel free to start with just one type of immunization and then build from there.
- The [maptools](https://github.com/Code4Nepal/maptools) project has examples of scripts that convert data into the form that is useful. It also includes mappings of `geo_code` to district name.