Fixed an error in locking-test

`locking-test` was hitting an error when passing the `client` object
to `distributed-lock`. It turns out that this is because
`distributed-lock` expects a `client-handler` object, not a simple
`client` object. I've added some code to create the right kind of
object so that the test will execute correctly.
Merge pull request #13 from holguinj/locking-test-fix

Fixed an error in locking-test