prepare RC

Author: MacGyer

composer.json

@@ -1,6 +1,6 @@
 {
     "name": "macgyer/yii2-materializecss",
-    "minimum-stability": "stable",
+    "minimum-stability": "RC",
     "description": "Materialize CSS implementation for Yii2",
     "keywords": ["materialize", "yii2", "widgets", "material design"],
     "homepage": "http://macgyer.github.io/yii2-materializecss",
@@ -13,7 +13,7 @@
             "role": "Developer"
         }
     ],
-    "version": "3.0.0-beta2",
+    "version": "3.0.0-RC",
     "require": {
         "php": ">=5.6.0",
         "yiisoft/yii2": "~2.0.0",