:+1: version and update docs

CHANGES.md

@@ -1,5 +1,8 @@
 # CHANGES
 
+## v4.2.8-RC
+
+* 
 
 ## v4.2.7
 

package.json

@@ -1,6 +1,6 @@
 {
   "name": "growi",
-  "version": "4.2.7-RC",
+  "version": "4.2.8-RC",
   "description": "Team collaboration software using markdown",
   "tags": [
     "wiki",