Delete the zip files. (#347)

[CarsonSlovoka]

Fix for issue #347

---

I have written a test, run under windows can pass the test.

[asticode]

I'm not fully satisfied with the way you've implemented this feature. Here's how I would do things:

1. change the mover interface to func(ctx context.Context, p Paths) (func() error, error) so that it returns a func
2. for both default movers, return a func() error that will remove the zip file. For instance, for astilectron:

func() (err error) {
  if err = os.RemoveAll(p.AstilectronDownloadDst()); err != nil {
    err = fmt.Errorf("removing %s failed: %w", p.AstilectronDownloadDst(), err)
    return
  }
}

3. then in provisionPackage, replace the move logic with something like:

// Move
var closeFunc func() error
if err = m(ctx, paths); err != nil {
	return fmt.Errorf("moving %s failed: %w", name, err)
}

// Make sure to close
defer func() {
  if err := closeFunc(); err != nil {
    // Only log the error
    p.l.Error(fmt.Errorf("closing failed: %w", err))
    return
  }
}()

[coveralls]

Coverage decreased (-0.5%) to 78.44% when pulling 6daec70 on CarsonSlovoka:is347 into 18cf1d5 on asticode:master.

[CarsonSlovoka]

Thank you for taking the time to help me do the code review. If you feel that teaching me is too slow, you can directly change it doesn't matter. I will then observe how you are dealing with it.

[asticode]

Thanks for this PR 👍