message: Fix minor indexmap version to keep 1.41 support
  indexmap 1.8 requires a higher rust version
diff: @@ -36,7 +36,7 @@ debug = true
  [dependencies]
  fixedbitset = { version = "0.4.0", default-features = false }
  -indexmap = { version = "1.6.2" }
  +indexmap = { version = "~1.7" }
  quickcheck = { optional = true, version = "0.8", default-features = false }
  serde = { version = "1.0", optional = true }
  serde_derive = { version = "1.0", optional = true }
  