Update proptest-derive dev-dependency from 0.3 to 0.6

Author: musicinmybrain

Cargo.toml

@@ -23,7 +23,7 @@ assert-dbg = { path = "assert-dbg" }
 collection_literals = "1.0.1"
 derive_more = "0.99.17"
 proptest = "1.1.0"
-proptest-derive = "0.3.0"
+proptest-derive = "0.6.0"
 quote = "1.0.23"
 trybuild2 = "1.0.0"