Look into notarizing .app on Mac

[qurben]

Notarizing the app on mac before deployment lowers the barrier of entry for users on Mac as they currently need to paste a command in the terminal, which can be quite scary.

[Minh-Than]

Since we talked about being able to open .dmg file without pasting codes in terminal a while ago, this might not be necessary. Maybe a few more Mac users to test out would be more conclusive though.