Natalie Oganesyan editorIn today’s TV news roundup, TNT announced “Snowpiercer’s” second season premiere date, and Epix set the premiere date for docuseries “By Whatever Means Necessary: The Times of Godfather of Harlem.”Natalie Zea will join the cast of “The Unicorn” alongside Walton Goggins, with whom she appeared on “Justified,” for an extended run, CBS announced.