Test(s) contain linux-specific path(s)

[BurtHarris]

There are a number of tests which validate filenames against linux-style paths. This generates errors when attempting development on native Windows. An example below:

● resolveUsingNpx › should install an npm module transparently

    expect(received).toMatch(expected)

    Expected pattern: /\.npm\/_npx\/\d*\/lib(64)?\/node_modules\/yarnhook\/index\.js$/
    Received string:  "C:\\Users\\burt_\\AppData\\Local\\npm-cache\\_npx\\34200\\node_modules\\yarnhook\\index.js"

      104 | 	it('should install an npm module transparently', async () => {
      105 | 		const result = await resolveUsingNpx('yarnhook');
    > 106 | 		expect(result).toMatch(
          | 		               ^
      107 | 			/\.npm\/_npx\/\d*\/lib(64)?\/node_modules\/yarnhook\/index\.js$/
      108 | 		);
      109 | 	});

On Windows, the result is valid, but does not match the regex.

The above is in packages/mrm/src/tests/index.spec.js, but I suspect
there are going to be a number of such issues, and rather than fixing them
individually, use of a vscode devcontainer will allow me to develop in a containerized
environment.