Update geocoder to version 1.2.5
Update Rails to version 4.1.6
Update taxonomy to Open Eligibility 2.0

I only updated the structure and the names of the categories. Although
OE 2.0 uses new IDs, I kept the same IDs as before because it makes it
easier to upgrade if you already assigned categories to services, and I
prefer the hierarchical ID system from version 1.0.

Closes #124.