Cannot specify bundle in animate(withGIFNamed:) method

[chris-shea]

prepareForAnimation(withGIFNamed:inBundle:…) allows for an arbitrary Bundle to passed in, with a default value of .main. However the higher abstraction of animate(withGIFNamed:), which in turn calls prepareForAnimation does not have an inBundle param. It would be helpful to add that param in order to facilitate referencing GIFs located somewhere other than Bundle.main when using that particular method.