add a starter toolkit to run the tests

[amtoine]

this PR adds a very simple toolkit.nu to run the tests of nu-git-manager without worrying about use nupm and the exact commands to run:

use toolkit.nu  # i use a hook for that
toolkit test

[melMass]

Nice! Can we check the availability of a module before "use"?
Like this could be catch and display a link to nupm's repo or something like that?

[amtoine]

Nice! Can we check the availability of a module before "use"? Like this could be catch and display a link to nupm's repo or something like that?

we might be able to use something like

$env.NU_LIB_DIRS? | default [] | append $NU_LIB_DIRS | each { ls --short-names $in | find "nupm" } | flatten | is-empty

this gives me false currently because Nupm is installed 😏