Use LXD for testing and working with codebase

[techtonik]

LXD is a native Linux docker replacement for https://linuxcontainers.org/lxd/

I ported LXD client lxc to Windows, so I can now command any node in my network to create container to checkout and test Gratipay code. The only problem that I can't access it from the network as I don't know its IP (or IP is invisible from outside).

The workflow so far:

### one time setup
#-- list LXD servers to work with
$ lxc remote list
#-- add main LXD server with Ubuntu images as `ilo` (will fetch images from it)
$ lxc remote add ilo images.linuxcontainers.org
#-- add LXD server from local network to run images on, name it `node`
#   (LXD should be installed on `node`)
lxc remote add node https://192.168.1.88
lxc remote set-default node

#-- launch Ubuntu wily on remote `node` under name `igc`
lxc launch ilo:ubuntu/wily/amd64 igc