* Update runc to 1.1.0 to get newer x/sys
...to fix building on Darwin with Go 1.18.
This required some code changes as opencontainers unfortunately introduced breaking changes in a minor revision.
However, those changes were to simpify the libcontainer factory initialization.
* Switch CircleCI image to cimg/go, update remote Docker version to 20.10
The go-dockerclient v1.7.0 now has an ability to specify events filter. But it's dependencies are also updated.
One of those dependencies is mountinfo and the same dependency is used by opencontainers/runc.
The problem is that mountinfo changed it's API and if we just update dockerclient then build is broken.
So we have to update both opencontainers/runc and go-dockerclient
Most containers expose some http port. We can open it in browser.
For simplicity we can just open first container's published port.
We'll determine the ip:port on container creation and store to meta "Web Port".
To open browser on any platform was added a new dependency github.com/pkg/browser which is very small
