Adds helper function for determining latitude and longitude of an address
Adds helper function for retrieving user from database
Replaces hard-coded work and home locations with latitude and longitude of work and home addresses
Adds utility function for determining the next time a given hour will occur (i.e. today or tomorrow)
Adds utility function for constructing server responses of the form {time: nextRequestTime, route: currentRoute}
Refactors add/update user route and routes route to use server response utility function