Update lxc requirement to 1.0
Docker-DCO-1.1-Signed-off-by: Michael Crosby <michael@crosbymichael.com> (github: crosbymichael)
Merge pull request #5945 from crosbymichael/lxc-version-bump

Update LXC requirement to 1.0
Update gorilla/mux, gorilla/context, and kr/pty deps

Docker-DCO-1.1-Signed-off-by: Andrew Page <admwiggin@gmail.com> (github: tianon)