Recreate remote temp dir if it no longer exists

[markafarrell]

Previously we do not check if self.good_temp_dir is actually good before using it.

If the path that self.good_temp_dir has been removed then we need to re-create it before trying to use that directory.

ansible_mitogen.target.is_good_temp_dir(self.good_temp_dir) ensure that that is the case.

Fixes #1061

[moreati]

Notes to myself

• ansible_mitogen.target.is_good_temp_dir(path) has a misleading name. It doesn't just do checks on an existing dir, it attempts to create the path.