meizumx64: always unrooted

This implements a workaround for the Meizu MX6. "su" in the rooted
version is broken from WA's perspective so all devices should be
considered unrooted.

wlauto/devices/android/meizumx6/__init__.py

@@ -0,0 +1,13 @@
+from wlauto import AndroidDevice
+
+
+class MeizuMX6(AndroidDevice):
+
+    name = 'meizumx6'
+
+    def is_rooted(self):
+        # "su" executable on a rooted Meizu MX6 is targeted
+        # specifically towards Android application and cannot
+        # be used to execute a command line shell. This makes it
+        # "broken" from WA prespective.
+        return False