#65: fixing a bug with unlocking an expired resource

[gnitsenko93]

Fixing an issue: #65

See my explanation in the issue thread.

[mike-marcacci]

Thanks SO much for the investigative effort here! It's incredibly helpful to have reproductions/PRs for issues, since otherwise it's very difficult to know if I'm talking about the same behavior as is being described in an issue :)

[coveralls]

Coverage remained the same at 100.0% when pulling f9f2e6a on gnitsenko93:master into e90e80a on mike-marcacci:master.