Bootstrap practice exercises (#774)
Bootstrap practice exercises (#774)

* Bootstrap pratice exercises

* Check if properties can fail, use TODO for types

* Rename exercise_path to exercise_snake_case

* Use Mix.Tasks.Format.run() instead of System.cmd

* Use Macro.underscore

* Mix.install to the top

* Update bin/bootstrap_practice_exercise.exs

Co-authored-by: Angelika Tyborska <f74aefa4323e6a2ebef59e7dc403f763b02378b1@fastmail.com>
exercism/xelixir