Updating to use latest Node, replacing geoip and time modules

[konklone]

This updates to the latest stable node, which meant leaving behind geoip for geoip-lite, and time for moment-timezone.

• The geoip-lite module is tricky to update using the commercial files - it requires hacking the .js file in the module to pull from a new URL (which ideally is a localhost URL using serve, which requires hacking it to use the http module instead of https...), and then symlinking into the node_modules dir for easier management of the resulting .dat files across deploys.
• The moment-timezone module works differently than time. The time module helpfully just wrapped the built-in Date object and imbued it with timezone smartness. The moment-timezone module has its own objects and parsing/formatting rules. I had to be slightly hacky about assembling a string and serializing it and then parsing it and then having Date parse the outputted format from that...but it's at least all contained inside a tiny function in christmas.js.

This should be a seamless transition for the web app, and for the API that IFTTT consumes. I'll need to do some testing from within IFTTT to make sure it's bug-free.

[konklone]

This works, and tested in IFTTT in both dev and production.