message: Bump to 0.28.0
  Looks like we've forgotten to do this so far on nightly!
diff: [package]
  name = "cargo"
  -version = "0.27.0"
  +version = "0.28.0"
  authors = ["Yehuda Katz <wycats@gmail.com>",
  "Carl Lerche <me@carllerche.com>",
  "Alex Crichton <alex@alexcrichton.com>"]
  