cleanup

Hi @stephen,

This path removes the dependency on `lodash` and also uses the list of http status codes provided by nodejs.

I stumbled upon this library when I was implementing a ROAP/AirTunes in nodejs. Found out that you had already done that when I had already gotten very far... I will still work on my implementation as a learning exercise and might submit some pull requests if it's appropriate.

My current step is to lift in `httplike` to use instead of the hack that I currently use to parse RTSP. I will make quite some changes and cleanup as I see fit. My goal is to make some small pull requests along the way and then you can choose if/what you want to merge.

Was there any specific reason to split the server/client parser? It seems like the only thing that differs is the parsing of the first line.

Really good work on all you libraries! Currently using `airsonos` to listen to a nice mixtape on my Sonos, very appreciated. If you find yourself in Stockholm and want free beer, I will deliver :beers:
Super nit-picky: do you mind adding in the `"use strict";` as the first line, as exists in the other files? I know I missed it originally here, but as long as we're cleaning things up.. :)