Refactor generate.js to use fs instead of bash commands

[ashryanbeats]

Bash commands are not compatible with Windows and non-POSIX systems.

[Newms34]

Made some changes to generate.js (and submitted pull request). It should work now, tho I'm admittedly not using fs. There seems to be issues with Windows and using multiple 'delete directory'-type commands in one line. In other words,
fs.rmdir('.\folderOne\ .\folderBlue\')
doesn't seem to work. Unless I'm missing something!