TestContainerProvisionerStarted fails due to unknown container type: lxd

[Martin Packman]

TestContainerProvisionerStarted fails on systems with go 1.3 or later but without some level of lxd support.

<http://reports.vapour.ws/releases/issue/5614b0e7749a5613c5aff2e0>

<http://reports.vapour.ws/releases/3365/job/run-unit-tests-wily-amd64/attempt/921>

FAIL: container_initialisation_test.go:174: ContainerSetupSuite.TestContainerProvisionerStarted
...
[LOG] 0:01.015 WARNING juju.provisioner not stopping machine agent container watcher due to error: initialising container infrastructure on host machine: unknown container type: lxd
[LOG] 0:01.015 ERROR juju.provisioner starting container provisioner for lxd: initialising container infrastructure on host machine: unknown container type: lxd
...
container_initialisation_test.go:192:
    s.assertContainerProvisionerStarted(c, m, ctype)
container_initialisation_test.go:171:
    // the container worker should have created the provisioner
    c.Assert(provisionerStarted, jc.IsTrue)
... obtained bool = false
...
OOPS: 101 passed, 3 FAILED
--- FAIL: TestPackage (59.59s)
FAIL
FAIL github.com/juju/juju/worker/provisioner 59.656s

[John A Meinel (jameinel)]

I'm pretty sure Tycho landed a patch for this to check if LXD is available even on things like gcc-go where the original runtime.Version() check wasn't working.