Broken symlink in provider builds

Currenlty after a 'make build' you'll get a symlink in build/provider/staging/platform that is broken:

➜  bitmask-systray git:(master) ✗ ls -al ./build/demo/staging/linux/bitmask-vpn
lrwxrwxrwx 1 kwadronaut kwadronaut 27 Oct  7 09:52 ./build/demo/staging/linux/bitmask-vpn -> ../../bin/linux/bitmask-vpn
➜  bitmask-systray git:(master) ✗ ls -al build/bin/linux/bitmask-vpn 
-rwxr-xr-x 1 kwadronaut kwadronaut 16471120 Oct  7 09:52 build/bin/linux/bitmask-vpn