Merge pull request #29 from savi-lang/remove/until-methods

Remove usage of `*_until`-style iteration methods.

Merge pull request #28 from savi-lang/update/latest-savi

Update for latest Savi syntax.

Merge pull request #26 from savi-lang/undo/fake-env

Refactor to undo the removal of the real `Env` from `Spec`.

Print a final statistic (#25)

Prints a final statistic similar to the following:

```
test result: OK. 39 passed; 0 failed; finished in 0s
```

Inspired by `cargo test` statistics.

Related issues: #16

Merge pull request #12 from savi-lang/add/async-tests

Add ability to test asynchronous actions.

Merge pull request #2 from savi-lang/deps/set-map-repo

Pull the `Map` library from `github:savi-lang/Map`.