Update parity-wasm crate

Signed-off-by: Sean Young <sean@mess.org>

Cargo.toml

@@ -18,7 +18,7 @@ regex = "1"
 num-bigint = "0.3"
 num-traits = "0.2"
 num-derive = "0.3"
-parity-wasm = "0.41"
+parity-wasm = "0.42"
 clap = "2.33"
 lazy_static = "1.4"
 hex = "0.4"