Merge pull request #81 from radu-matei/fix/update-dockerhub-endpoint

Update default `docker.io` registry

src/reference.rs

@@ -108,7 +108,7 @@ impl Reference {
     pub fn resolve_registry(&self) -> &str {
         let registry = self.registry();
         match registry {
-            "docker.io" => "registry-1.docker.io",
+            "docker.io" => "index.docker.io",
             _ => registry,
         }
     }