chore: update package meta points to upstream repo

Author: tisonkun

Cargo.toml

@@ -4,6 +4,6 @@ version = "1.0.1"
 rust-version = "1.6"
 license = "Apache-2.0 OR MIT"
 description = "Traits for key comparison in maps."
-repository = "https://github.com/cuviper/equivalent"
+repository = "https://github.com/indexmap-rs/equivalent"
 keywords = ["hashmap", "no_std"]
 categories = ["data-structures", "no-std"]