message: Travis, please test traits with no_std
diff: @@ -10,6 +10,10 @@ for package in bigint complex integer iter rational traits; do
  cargo test --manifest-path $package/Cargo.toml
  done
  +# Only num-tratis supports no_std at the moment.
  +cargo build --manifest-path traits/Cargo.toml --no-default-features
  +cargo test --manifest-path traits/Cargo.toml --no-default-features
  +
  # Each isolated feature should also work everywhere.
  for feature in '' bigint rational complex; do
  cargo build --verbose --no-default-features --features="$feature"
  