matthyx: do not install docker with curl

JobBuild
d42321dc
05-13 13:25		 ba663289
05-13 11:47		 62178691
05-02 13:24		 109753
05-02 13:24		 unknown
05-02 13:21
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pull-kubernetes-conformance-kind-ipv6-parallel 1525105014857535488 1525080215515041792 1521117911115108352 1521117710728040448
pull-kubernetes-dependencies 1525105014899478528 1525080215565373440 1521117892207185920 1521117710761594880
pull-kubernetes-e2e-gce-100-performance 1525105015268577280 1525080215875751936 1521117911505178624 1521117716402933760
pull-kubernetes-e2e-gce-ubuntu-containerd 1525105014933032960 1525080215598927872 1521117893037658112 1521117710803537920
pull-kubernetes-e2e-kind 1525105015008530432 1525080215674425344 1521117896405684224 1521117711399129088
pull-kubernetes-e2e-kind-ipv6 1525105015046279168 1525080215712174080 1521117898918072320 1521117712628060160
pull-kubernetes-integration 1525105014970781696 1525080215632482304 1521117894719574016 1521117710841286656
pull-kubernetes-node-e2e-containerd 1525105015209857024 1525080215829614592 1521117903951237120 1521117715136253952
pull-kubernetes-typecheck 1525105015688007680 1525080216349708288 1521117905641541632 1521117716822364160
pull-kubernetes-unit 1525105015142748160 1525080215787671552 1521117902273515520 1521117714733600768
pull-kubernetes-verify 1525105017369923584 1525080218031624192 1521117909424803840 1521117718504280064
pull-kubernetes-verify-govet-levee 1525105016522674176 1525080217188569088 1521117906505568256 1521117717661224960