Merge pull request #34 from somehowchris/renovate/validator-0.x

fix(deps): update rust crate validator to 0.18.0

Cargo.toml

@@ -19,7 +19,7 @@ path = "src/lib.rs"
 rocket = { version = "0.5.0", default-features = false, features = [
     "json",
 ] }
-validator = { version = "0.16.1", features = ["derive"] }
+validator = { version = "0.18.0", features = ["derive"] }
 
 [[example]]
 name = "json-validation"