Change version to 1.1.1 (#12)

This PR changes version to 1.1.1 to prepare to release 1.1.1.

/kind cleanup

```release-note
None
```

Author: JohnNiang

gradle.properties

@@ -1 +1 @@
-version=1.0.0-SNAPSHOT
+version=1.1.1-SNAPSHOT

src/main/resources/plugin.yaml

@@ -6,7 +6,7 @@ metadata:
 spec:
   enabled: true
   # 'version' is a valid semantic version string (see semver.org).
-  version: 1.0.0-beta.1
+  version: 1.1.1
   requires: ">=2.4.0"
   author:
     name: Halo OSS Team