Add Windows CI for msvc 2017 and msys2

Currently the container is based upon a windows 1607 image
and requires a runner with a server/hyper-v 1607 host
to be able to execute.

There are plan on moving the runner to a 1807 later.
4 jobs for alatiera/initial-ci in 2 minutes and 35 seconds (queued for 4 seconds)
Status Job ID Name Coverage
  Build
passed #427237
debian sid

00:02:29

passed #427240
docker windows 1607
msys2

00:01:02

passed #427238
docker windows 1607
vs2017 amd64

00:01:05

passed #427239
docker windows 1607
vs2017 x86

00:01:04