message: Make everyone use a consistent itertools
  Summary: Better to be consistent.
diff: @@ -28,7 +28,7 @@ lalrpop-util = "0.19.7"
  indexmap = { version = "1.6", features = ["serde-1"] }
  indenter = { version = "0.3.3", features = ["std"] }
  indoc = "1.0"
  -itertools = "0.9"
  +itertools = "0.10.0"
  once_cell = "1.3"
  bumpalo = "3.8"
  paste = "1.0"
  