Adds deleteUser route and refactors server routes
Adds ability to update user settings
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