The Golang base images switch to buster, which causes some breakage
in networking and packages that are no  longer available; (`btrfs-tools`
is now an empty package, and `libprotobuf-c0-dev` is gone).

Some of out tests also start faiilng on stretch, and will have to be
investigated further;

```
15:13:06 --- FAIL: TestRenameAnonymousContainer (3.37s)
15:13:06     rename_test.go:168: assertion failed: 0 (int) != 1 (inspect.State.ExitCode int): container a7fe866d588d65f353f42ffc5ea5288e52700384e1d90850e9c3d4dce8657666 exited with the wrong exitcode:

15:13:38 --- FAIL: TestHostnameDnsResolution (2.23s)
15:13:38     run_linux_test.go:128: assertion failed:
15:13:38         --- ←
15:13:38         +++ →
15:13:38         @@ -1 +1,2 @@
15:13:38         +ping: bad address 'foobar'
15:13:38
15:13:38
15:13:38     run_linux_test.go:129: assertion failed: 0 (int) != 1 (res.ExitCode int)
```

Signed-off-by: Sebastiaan van Stijn <github@gone.nl>