Handle trailing build metadata in Python version string

Don't fail Python versions when the version string contains trailing
build metadata after the `+` (as per: https://semver.org/#spec-item-10).

src/version.rs

@@ -15,7 +15,7 @@ impl Version {
     pub fn scan_bytes(data: &[u8]) -> Result<Version, Error> {
         lazy_static! {
             static ref RE: Regex = Regex::new(
-                r"((2|3)\.(3|4|5|6|7|8|9|10|11)\.(\d{1,2}))((a|b|c|rc)\d{1,2})?\+? (.{1,64})"
+                r"((2|3)\.(3|4|5|6|7|8|9|10|11)\.(\d{1,2}))((a|b|c|rc)\d{1,2})?(\+[0-1a-z]*)? (.{1,64})"
             )
             .unwrap();
         }