Improve performance of project delete for Windows

[AWolf81]

Describe the bug Guppy freezes during project deletion on Windows. Please have a look at the screen recording and the message Keine Rückmeldung means not responding.

I think this is a problem with the deletion of node_modules folder. I'll have a look at the issue and I think it could be improved by using rimraf for delete process.

To Reproduce

1. Create Project
2. Delete project from disk

Expected behavior Delete project with-out freezing.

Screenshots

Environment (please complete the following information):

• OS: Windows 10
• Version: master
• Node version: v8.11.1

Things to discuss:

• At the moment, Guppy moves the project into trash and that's probably causing the problem. I think we could delete the project completely as a project can have over 100 MB with many small files. Or as a compromise delete the node_modules folder and move the rest to trash. I think I'll start with this.

[joshwcomeau]

Or as a compromise delete the node_modules folder and move the rest to trash. I think I'll start with this.

That sounds good to me - that way the user can restore a deleted project, and node_modules are easy enough to reinstall (although not really through Guppy... we should add a "reinstall modules" button at some point).

[joshwcomeau]

Fixed in #280