Error [Configure VM drush aliases for vagrant user.] when using multiple site

[sanglt]

The error is: ~/.drush directory does not exist. After manual add that directory and run: vagrant provision, its work.

So we should make that directory first, before do the task.

[geerlingguy]

This wasn't an issue on my local build (OS X 10.10 with Ubuntu 14.04), but I can see how this could error out in some situations, so I think I can fix it by simply adding two tasks to make sure both ~/.drush directories exist prior to writing the drush alias files. Testing now...