message: Updated to SDL 0.28
diff: @@ -19,12 +19,12 @@ name = "ggez"
  path = "src/lib.rs"
  [dependencies.sdl2]
  -version = "0.27.2"
  +version = "0.28"
  default-features = false
  features = ["image", "mixer"]
  [dependencies]
  -sdl2-sys = "0.27.2"
  +sdl2-sys = "0.27"
  rusttype = "0.2"
  rand = "0.3"
  zip = "0.1"
  