manager runs on Mac, and other openpilot for PC fixes (#1037)

* use the openpilot/persist directory on PC

* manager runs on mac

* sim runs w/o carla

* fix params location in test

* that rmtree can fail and it's okay

* refactor params clear functionality

* set PARAMS_PATH

common/basedir.py

@@ -1,4 +1,11 @@
 import os
 BASEDIR = os.path.abspath(os.path.join(os.path.dirname(os.path.realpath(__file__)), "../"))
 
+from common.android import ANDROID
+if ANDROID:
+  PERSIST = "/persist"
+  PARAMS = "/data/params"
+else:
+  PERSIST = os.path.join(BASEDIR, "persist")
+  PARAMS = os.path.join(BASEDIR, "persist", "params")