docker: fix cpu tests

[bergwolf]

We should take the initial cpu count when setting cpu constraints.
IOW, if there is already enough cpu in the vm for a container, we
should not hotplug more CPUs.

Depends-on: kata-containers/runtime#696
Fixes: #705

[jodh-intel]

lgtm

But looking at the CI logs suggests the depends-on is broken:

This PR depends on repository: kata-containers/runtime and pull request: 696
package kata-containers/runtime: unrecognized import path "kata-containers/runtime" (import path does not begin with hostname)

[chavafg]

@bergwolf can you rebase your PR with latest changes? There is a fix that solves the Depends-on issue.

[jcvenegas]

@devimc ping

[jcvenegas]

Summarizing 15 Failures:

[Fail] Update number of CPUs Update CPU period and quota [It] should have 2 CPUs 
/tmp/jenkins/workspace/kata-containers-tests-fedora-27-PR/go/src/github.com/kata-containers/tests/integration/docker/cpu_test.go:287

[Fail] Update number of CPUs Update CPU period and quota [It] should have 3 CPUs 
/tmp/jenkins/workspace/kata-containers-tests-fedora-27-PR/go/src/github.com/kata-containers/tests/integration/docker/cpu_test.go:287

[Fail] Update number of CPUs Update CPU period and quota [It] should have 1 CPUs 
/tmp/jenkins/workspace/kata-containers-tests-fedora-27-PR/go/src/github.com/kata-containers/tests/integration/docker/cpu_test.go:287

[Fail] Update number of CPUs Update CPU constraint [It] should have 1 CPUs 
/tmp/jenkins/workspace/kata-containers-tests-fedora-27-PR/go/src/github.com/kata-containers/tests/integration/docker/cpu_test.go:309

[Fail] Update number of CPUs Update CPU constraint [It] should have 2 CPUs 
/tmp/jenkins/workspace/kata-containers-tests-fedora-27-PR/go/src/github.com/kata-containers/tests/integration/docker/cpu_test.go:309

[Fail] Update number of CPUs Update CPU constraint [It] should have 2 CPUs 
/tmp/jenkins/workspace/kata-containers-tests-fedora-27-PR/go/src/github.com/kata-containers/tests/integration/docker/cpu_test.go:309

[Fail] Update number of CPUs Update CPU constraint [It] should have 3 CPUs 
/tmp/jenkins/workspace/kata-containers-tests-fedora-27-PR/go/src/github.com/kata-containers/tests/integration/docker/cpu_test.go:309

[Fail] Update number of CPUs Update CPU constraint [It] should have 3 CPUs 
/tmp/jenkins/workspace/kata-containers-tests-fedora-27-PR/go/src/github.com/kata-containers/tests/integration/docker/cpu_test.go:309

[Fail] Hot plug CPUs container with CPU period and quota [It] should have 2 CPUs 
/tmp/jenkins/workspace/kata-containers-tests-fedora-27-PR/go/src/github.com/kata-containers/tests/integration/docker/cpu_test.go:96

[Fail] Hot plug CPUs container with CPU period and quota [It] should have 3 CPUs 
/tmp/jenkins/workspace/kata-containers-tests-fedora-27-PR/go/src/github.com/kata-containers/tests/integration/docker/cpu_test.go:96

[Fail] Hot plug CPUs container with CPU period and quota [It] should have 1 CPUs 
/tmp/jenkins/workspace/kata-containers-tests-fedora-27-PR/go/src/github.com/kata-containers/tests/integration/docker/cpu_test.go:96

[Fail] Hot plug CPUs container with CPU constraint [It] should have 1 CPUs 
/tmp/jenkins/workspace/kata-containers-tests-fedora-27-PR/go/src/github.com/kata-containers/tests/integration/docker/cpu_test.go:115

[Fail] Hot plug CPUs container with CPU constraint [It] should have 2 CPUs 
/tmp/jenkins/workspace/kata-containers-tests-fedora-27-PR/go/src/github.com/kata-containers/tests/integration/docker/cpu_test.go:115

[Fail] Hot plug CPUs container with CPU constraint [It] should have 2 CPUs 
/tmp/jenkins/workspace/kata-containers-tests-fedora-27-PR/go/src/github.com/kata-containers/tests/integration/docker/cpu_test.go:115

[Fail] Hot plug CPUs container with CPU constraint [It] should have 3 CPUs 
/tmp/jenkins/workspace/kata-containers-tests-fedora-27-PR/go/src/github.com/kata-containers/tests/integration/docker/cpu_test.go:115

Ran 200 of 211 Specs in 992.647 seconds
FAIL! -- 185 Passed | 15 Failed | 0 Pending | 11 Skipped --- FAIL: TestIntegration (1018.22s)

[bergwolf]

I'll drop this one for now since @devimc has a valid use case and we might introduce a new option to control the behavior.