Request unrestricted access to files during first startup

[stv0g]

From #4:

I think the larger issue with the newer OS is permissions on folders. Currently with the newest OS I am getting constant requests to allow permission to git-annex-turtle, it doesn't seem to be saving these permissions permanently…

I can confirm this.

I worked around this, by granting the app full access to my files via the MacOS settings:

1. Open "System Settings"
2. Goto "Privacy & Security"
3. Goto "Full disk access"
4. Add git-annex-turtle, by clicking on "+" and selecting the app from the /Applications folder