Merge pull request #22 from crlf0710/patch-1

Bump version to 0.13

Author: eddyb

Cargo.toml

@@ -4,7 +4,7 @@ description = "Union-find, congruence closure, and other unification code. Based
 license = "MIT/Apache-2.0"
 homepage = "https://github.com/nikomatsakis/ena"
 repository = "https://github.com/nikomatsakis/ena"
-version = "0.12.0"
+version = "0.13.0"
 authors = ["Niko Matsakis <[email protected]>"]
 readme = "README.md"
 keywords = ["unification", "union-find"]