Add a test for IP v6

src/lib.rs

@@ -85,7 +85,7 @@ impl fmt::Debug for Ipv6Network {
 
 #[cfg(test)]
 mod test {
-    use std::net::Ipv4Addr;
+    use std::net::{Ipv4Addr, Ipv6Addr};
     use super::*;
 
     #[test]
@@ -93,4 +93,10 @@ mod test {
         let cidr = Ipv4Network::new(Ipv4Addr::new(77, 88, 21, 11), 24);
         assert_eq!(cidr.prefix(), 24);
     }
+
+    #[test]
+    fn test_create_v6() {
+        let cidr = Ipv6Network::new(Ipv6Addr::new(0, 0, 0, 0, 0, 0, 0, 1), 24);
+        assert_eq!(cidr.prefix(), 24);
+    }
 }