fails:Module#remove_class_variable removes class variable
fails:Module#remove_class_variable returns the value of removing class variable
fails:Module#remove_class_variable removes a class variable defined in a metaclass
fails:Module#remove_class_variable raises a NameError when passed a symbol with one leading @
fails:Module#remove_class_variable raises a NameError when passed a symbol with no leading @
fails:Module#remove_class_variable raises a NameError when an uninitialized class variable is given
