Fix path parsing for custom validators

`::foo::bar` isn't a valid ident in syn 0.12. This lead to some code
failing to compile if it was using paths as custom validators.
This fixes it and adds a test.

1 files changed, 6 insertions, 0 deletions

diff --git a/validator_derive/tests/run-pass/custom.rs b/validator_derive/tests/run-pass/custom.rs
index 3a2a396..dff6375 100644
--- a/validator_derive/tests/run-pass/custom.rs
+++ b/validator_derive/tests/run-pass/custom.rs
@@ -10,6 +10,12 @@ struct Test {
     s: String,
 }
 
+#[derive(Validate)]
+struct TestPath {
+    #[validate(custom = "::validate_something")]
+    s: String,
+}
+
 fn validate_something(s: &str) -> Result<(), ValidationError> {
     Ok(())
 }