Re-running watchmaker results in a traceback

[lorengordon]

The first watchmaker run places all the formulas in the correct location, but the second run blows up cuz the formula directories already exist.

Traceback (most recent call last):
  File "/usr/bin/watchmaker", line 11, in <module>
    load_entry_point('watchmaker==0.1.3.dev0', 'console_scripts', 'watchmaker')()
  File "/usr/lib/python2.6/site-packages/watchmaker/cli.py", line 109, in main
    sys.exit(watchmaker_client.install())
  File "/usr/lib/python2.6/site-packages/watchmaker/__init__.py", line 385, in install
    workers_manager.worker_cadence()
  File "/usr/lib/python2.6/site-packages/watchmaker/managers/workers.py", line 38, in worker_cadence
    salt.install()
  File "/usr/lib/python2.6/site-packages/watchmaker/workers/salt.py", line 419, in install
    self._build_salt_formula(self.salt_srv)
  File "/usr/lib/python2.6/site-packages/watchmaker/workers/salt.py", line 396, in _build_salt_formula
    formulas_conf = self._get_formulas_conf()
  File "/usr/lib/python2.6/site-packages/watchmaker/workers/salt.py", line 159, in _get_formulas_conf
    os.path.join(self.salt_formula_root, '', formula))
  File "/usr/lib64/python2.6/shutil.py", line 142, in copytree
    os.makedirs(dst)
  File "/usr/lib64/python2.6/os.py", line 157, in makedirs
    mkdir(name, mode)
OSError: [Errno 17] File exists: '/srv/salt/formulas/ash-windows-formula'