ValueTracker must support increment also using +=

Just what the title says. Here’s an example

class Test(Scene):
    def construct(self):
        tracker = ValueTracker(0.0)
        tracker.set_value(2.0)
        print(tracker.get_value()) # -> 2.000
        tracker.increment_value(3.0)
        print(tracker.get_value()) # -> 5.000
        tracker += 4.0 # NEW proposed feature
        print(tracker.get_value()) # -> 9.000

[nilaybhatia]

Yeah @huguesdevimeux , I forgot, my bad. Will keep it in mind now.

[huguesdevimeux]

@naveen521kk Please please assign yourself when you’re working on an issue.