CNN’s Don Lemon wrapped up his eight-year run as host of “Don Lemon Tonight” with an emotional farewell on his show Friday. The outspoken 56-year-old discussed the difficulty of hosting the ratings-challenged 10 p.m. show and aired a montage of his greatest hits. “I know I was not always perfect because no one is perfect,” Lemon said. “There are immense pressures that come with this job, and in particular, this time slot at 10 p.m., when people are going to bed. So sometimes, all I could do — I’m gonna be honest with you — is just smile and just...