Changed @sondr3/minitest to be a peer dependency

[ijlee2]

Background

In a Node project, when @sondr3/minitest is installed as a dependency, we can run its executable (called mt) to run tests easily:

/* Example: @codemod-utils/ast-javascript */
{
  "scripts: {
    "test": "./build.sh --test && mt dist-for-testing --quiet"
  }
}

@codemod-utils/tests@v0.2.5 (and earlier versions) had @sondr3/minitest as a dependency so that the consuming project wouldn't need to install it themselves. However, I couldn't figure out how to update the test script, i.e. how to replace the command mt with node_modules/<some path>/mt.

What changed?

For simplicity (that is, allow the test script to continue to show the mt command), we'll ask the consuming project to install @sondr3/minitest as a development dependency. This already happens when we use @codemod-utils/cli to create a codemod project.

In effect, removing @sondr3/minitest as a dependency from @codemod-utils/tests will prevent the consuming project from potentially installing two versions of @sondr3/minitest.