chore: set package version to 3.1.1

Author: gonuit

CHANGELOG.md

@@ -1,3 +1,6 @@
+## 3.1.1
+- Fix:
+  - Fixed *durations* parameter of *CustomRefreshIndicator* widget. Reported by [@jccd1996](https://github.com/jccd1996) in [#58](https://github.com/gonuit/flutter-custom-refresh-indicator/issues/58).
 ## 3.1.0
 - Experimental: 
   - Added `ClampingWithOverscrollPhysics` scroll physics, that together with indicator controller allows handling overscroll correctly.

example/pubspec.lock

@@ -47,7 +47,7 @@ packages:
       path: ".."
       relative: true
     source: path
-    version: "3.1.0"
+    version: "3.1.1"
   fake_async:
     dependency: transitive
     description:

pubspec.yaml

@@ -1,6 +1,6 @@
 name: custom_refresh_indicator
 description: Widget that makes it easy to implement a custom pull to refresh gesture.
-version: 3.1.0
+version: 3.1.1
 repository: https://github.com/gonuit/flutter-custom-refresh-indicator
 issue_tracker: https://github.com/gonuit/flutter-custom-refresh-indicator/issues
 homepage: https://github.com/gonuit/flutter-custom-refresh-indicator