Add test for virtual machines and local clocks

This commit provides a spec test for pull request #49 and commit
01273c53f1cf2015c3ff5a9f704828225d900e03 which specifies that virtual
machines should not use the local clock. This test attempts to protect
against a regression on that statement.
Merge pull request #54 from puppetlabs/spec_test/pull_49

Add test for virtual machines and local clocks