Update README

Author: thombashi

README.md

@@ -12,7 +12,7 @@ Add this to your `.pre-commit-config.yaml`:
 ```yaml
 repos:
     - repo: https://github.com/cybozu/pre-commit-jsonnet
-      rev: v0.1.0
+      rev: v0.2.0
       hooks:
           - id: jsonnet-fmt
             args: ["--test"]  # you can use arbitrary options of jsonnetfmt command