This lint should also be applied to the excersies,
but I am not certain how to run it for all non-crate individual files.
To re-run:
```
rustup run nightly cargo clippy --fix -- -A clippy::all -W clippy::uninlined_format_args
```
This new feature can be accessed by invoking rustlings with --nocapture.
Both unit and integration tests added.
closes#262
BREAKING CHANGES:
The following function take a new boolean argument:
* `run`
* `verify`
* `test`
* `compile_and_test`
`watch` and `verify` do prompt the user to actively move to the
next exercise. This change fixes `run` to never prompt. Previously
it was inconsistent between "test" and "compile" exercises.
BREAKING CHANGE: we again change the behavior of the `run` command