Jimmy Carter on Iran, racism, painting and life at 90

Jimmy Carter, who had a terrible time with Iran as President from 1977 to 1981 -- especially because 52 Americans were held hostage by Iran -- tells Dan Raviv on the CBS News Weekend Roundup that a nuclear deal with Iran can be trusted, if Secretary of State Kerry endorses it.  Carter also talks about his new book, "A Full Life: Reflections at 90."