Add a lockfile and upgrade dependencies

`ctest` is horribly inconsistent across targets for unclear reasons. It
seems unlikely, but one possibility is that different versions of
dependencies are getting used on different platforms. Attempt to
mitigate this by adding a lockfile and upgrading all `Cargo.toml`
dependencies to the latest version.

Author: tgross35

.gitignore

@@ -1,3 +1,2 @@
 target
-Cargo.lock
 *~