remove when httputil.NewClientConn when not in hijack

Docker-DCO-1.1-Signed-off-by: Victor Vieux <vieux@docker.com> (github: vieux)
move hijack to it's own file

Docker-DCO-1.1-Signed-off-by: Victor Vieux <vieux@docker.com> (github: vieux)
fix https

Docker-DCO-1.1-Signed-off-by: Victor Vieux <vieux@docker.com> (github: vieux)
Update vendored deps that have a proper version number to use said specific versions

Docker-DCO-1.1-Signed-off-by: Andrew Page <admwiggin@gmail.com> (github: tianon)
Merge pull request #5544 from vieux/cleanup_api_client

Cleanup api client
It's its.
Merge pull request #5580 from tianon/update-vendor-versions

Update vendored deps that have a proper version number to use said specific versions
Merge pull request #5604 from nirvdrum/patch-1

It's its.