Implement a geohashing restful service, as described in XKCD:

Given: GET /geohash?lat=37.421542&lon=-122.085589

Expected Output from API: => 200 application/json {lat: 37.857713, lon: -122.544543}

• Dow Opening Query:

https://query.yahooapis.com/v1/public/yql?q=select%20*%20from%20yahoo.finance.quotes%20where%20symbol%20in%20(%22%5ENDX%22%2C%22INDU%22)&format=json&diagnostics=true&env=store%3A%2F%2Fdatatables.org%2Falltableswithkeys&callback=

• Accept lat/lon as POST
• Abstract the geohashing logic into a separate module
• Cache the dow opening API call to occur once per day
• Write unit tests for the module and/or TDD your way there!
• Use pipe instead of a callback to handle the stock call
• Implement a "cacheable" function that takes as input a function to cache, and a cacheKey such that when you compose the functions together ie: cacheable(myFunc() {..}, "my-cache-key") you are returned a function that caches results for that key; use this function as your caching strategy
• Implement a promise-based API
• Make the promise-based API also handle callbacks :)