Lewis Hamilton is entering his 20th season in Formula One, but he says he's not considering retirement until he accomplishes one more milestone -- competing in Africa. The 41-year-old Ferrari superstar relayed his wishes ahead of the Australian Grand Prix on Thursday ... when he was asked what city in Africa would be his dream spot to host a race. Hamilton gave a lengthy response ... explaining how he's been "fighting in the background" for a return to Africa for more than half a decade. The