tweaking CompassHeading tests and adding new constructor tests
tweaking CompassHeading tests and adding new constructor tests

apache/cordova-mobile-spec,apache/cordova-mobile-spec,corimf/cordova-mobile-spec,ollie314/cordova-mobile-spec,ollie314/cordova-mobile-spec,apache/cordova-mobile-spec,apache/cordova-mobile-spec,polyvi/xface-mobile-spec,corimf/cordova-mobile-spec,ollie314/cordova-mobile-spec,polyvi/xface-mobile-spec,corimf/cordova-mobile-spec,corimf/cordova-mobile-spec,corimf/cordova-mobile-spec,lorinbeer/cordova-mobile-spec,apache/cordova-mobile-spec,ollie314/cordova-mobile-spec,polyvi/xface-mobile-spec,ollie314/cordova-mobile-spec