cache property not available

[sambrightman]

I'm getting this when running teamcity-messages tests for pylint:

Traceback (most recent call last):
   File "/tmp/teamcity-python-venv/27pyst27pynt/lib/python2.7/site-packages/_pytest/main.py", line 80, in wrap_session
     config.do_configure()
   File "/tmp/teamcity-python-venv/27pyst27pynt/lib/python2.7/site-packages/_pytest/config.py", line 618, in do_configure
     self.hook.pytest_configure(config=self)
   File "/tmp/teamcity-python-venv/27pyst27pynt/lib/python2.7/site-packages/_pytest/core.py", line 521, in __call__
     return self._docall(self.methods, kwargs)
   File "/tmp/teamcity-python-venv/27pyst27pynt/lib/python2.7/site-packages/_pytest/core.py", line 528, in _docall
     firstresult=self.firstresult).execute()
   File "/tmp/teamcity-python-venv/27pyst27pynt/lib/python2.7/site-packages/_pytest/core.py", line 394, in execute
     res = method(*args)
   File "/tmp/teamcity-python-venv/27pyst27pynt/lib/python2.7/site-packages/pytest_pylint.py", line 164, in pytest_configure
     config.pylint = PylintPlugin(config)
   File "/tmp/teamcity-python-venv/27pyst27pynt/lib/python2.7/site-packages/pytest_pylint.py", line 176, in __init__
     self.mtimes = config.cache.get(HISTKEY, {})
 AttributeError: 'Config' object has no attribute 'cache'

which appears to be related to #83. Maybe pytest-dev/pytest@e478f66 is related? I can't see why the cacheprovider has not yet set the cache property, since it should be loaded first.

[orf]

We ran into this while running pytest with -p no:cacheprovider. Removing this fixed it.

[cs-cordero]

I also ran this while running pytest with -p no:cacheprovider. I think it'd be a good idea to allow users to disable the cache if we wanted to.