CAMBRIDGE, Mass. (AP) — Social media is buzzing over a Harvard graduate's poetic commencement speech, which has garnered millions of views and the attention of celebrities.Donovan Livingston, who received his master's degree in education, addressed his classmates Wednesday with a spoken-word poem outlining the historic obstacles that have prevented African-Americans from getting an education.The speech begins with a quote by education reformer Horace Mann and [...]