Add api-pipeline image to leverage-devbackend

@lottspot has already done the work of setting up an image with libpostal. But it needs to be fleshed out to run the scripts in api-pipeline before it can go into leverage-devbackend.

[lottspot]

The base Dockerfile and build files can be found in the leverage-devbackend repo

[lottspot]

Note that libpostal is not compiled directly from source, but is a Arch Linux PKGBUILD script based on the one in the AUR, because I'm lazy and didn't want to do it from scratch. There may be a better way to do it (or a better base image to use), but if you're lazy like me, that part of the work is done.