By Marvin Dotiyal, Contributor [Columbia; 2016] Rating: 3/10 Key Tracks: “All We Know,” “Closer,” “Inside Out” The DJ duo The Chainsmokers once again prove themselves to be mediocre artists in their latest release, Collage. In this five-track EP, The Chainsmokers bring in new artists as a lousy attempt to not only spice up the EP, but also to attract…