Linuxkit v0.3 & updated tools in CI

[ijc]

I ran scripts/update-linuxkit-hashes.sh v0.3 and then bumped some of the versions in the CI config by hand.

[ijc]

I'm in the process of running the rtf tests now.

[ijc]

The kubelet build took ages (anecdotally it seems slower than I remember) so rtf is still running.

It occurred to me a bit late that this would be a good time to bump the version of docker in yml/docker.yml too (from 17.12 to 18.03). I'll tack that on the end in a moment.

[ijc]

Before I bumped Docker:

LABELS: linux, Debian, testing, amd64
ID: f0e963be-0c91-4c77-974a-017e860fd30a
[PASS    ] kubernetes.smoke.cri-bridge 351.40s
[PASS    ] kubernetes.smoke.cri-weave 254.85s
[PASS    ] kubernetes.smoke.docker-bridge 272.75s
[PASS    ] kubernetes.smoke.docker-weave 280.24s
[SUMMARY ] LogDir: f0e963be-0c91-4c77-974a-017e860fd30a
[SUMMARY ] Version: testing
[SUMMARY ] Passed: 4
[SUMMARY ] Failed: 0
[SUMMARY ] Cancelled: 0
[SUMMARY ] Skipped: 0
[SUMMARY ] Duration: 1159.53s

After I bumped Docker:

LABELS: linux, Debian, testing, amd64
ID: eb16b5bf-92ce-491a-92ff-6d6e7d755b41
[PASS    ] kubernetes.smoke.cri-bridge 201.75s
[PASS    ] kubernetes.smoke.cri-weave 248.52s
[PASS    ] kubernetes.smoke.docker-bridge 264.14s
[PASS    ] kubernetes.smoke.docker-weave 260.15s
[SUMMARY ] LogDir: eb16b5bf-92ce-491a-92ff-6d6e7d755b41
[SUMMARY ] Version: testing
[SUMMARY ] Passed: 4
[SUMMARY ] Failed: 0
[SUMMARY ] Cancelled: 0
[SUMMARY ] Skipped: 0
[SUMMARY ] Duration: 974.85s

Merging.