Fixing #1556 VERR_ACCESS_DENIED

This should fix #1556 "vagrant driver writes vagrant-console-log to installation dir instead of $TMPDIR". I just added `'modifyvm', :id, '--uartmode1', 'disconnected'` to the default Vagrantfile of Molecule.

Signed-off-by: Jonas Hecht <jonas.hecht@codecentric.de>

molecule/driver/vagrant.py

@@ -79,6 +79,7 @@ class Vagrant(base.Base):
               gui: True
             provider_raw_config_args:
               - "customize ['modifyvm', :id, '--cpuexecutioncap', '50']"
+              - "customize ['modifyvm', :id, '--uartmode1', 'disconnected']"
             provider_override_args:
               - "vm.synced_folder './', '/vagrant', disabled: true, type: 'nfs'"
             provision: True