fix tests

[pi0]

I'm not sure if this is even a good idea to pass the full path to importFresh, but as tests seem to fail with latest versions of dependencies, this PR at least resolves the problem.

---

Stack trace:

  Rejected promise returned by the test. Reason:

  Error {
    code: 'MODULE_NOT_FOUND',
    message: 'Cannot find module \'.\'',
  }

  resolveFileName (node_modules/resolve-from/index.js:18:39)
  resolveFrom (node_modules/resolve-from/index.js:32:9)
  module.exports (node_modules/resolve-from/index.js:35:41)
  module.exports.moduleId (node_modules/import-fresh/index.js:11:19)
  test.js:56:23

[sindresorhus]

I have fixed the tests in master by updating import-fresh.