The goal is to remove function from `docker_utils.go` and setup
simple, one-responsability package that can be well tested ; and to
ease writing request.
This moves all the calls to `sockRequest` (and similar methods) to
their counterpart in the `request` package.
This introduce `request.Do` to write easier request (with functional
argument to easily augment the request) with some pre-defined function
for the most used http method (i.e. `request.Get`, `request.Post` and
`request.Delete`).
Few of the `sockRequest` call have been moved to `request.Do` (and
`Get`, etc.) to showcase the usage of the package. There is still a
whole lot to do.
Signed-off-by: Vincent Demeester <vincent@sbr.pm>
