Update version and README.md

Author: takezoe

README.md

@@ -4,6 +4,7 @@ This is an example of GitBucket plug-in. This plug-in provides code snippet repo
 
 Plugin version | GitBucket version
 :--------------|:--------------------
+3.13.x         | 3.13.x
 3.12.x         | 3.12.x
 3.11.x         | 3.11.x
 3.10.x         | 3.10.x

project/build.scala

@@ -7,7 +7,7 @@ object MyBuild extends Build {
 
   val Organization = "jp.sf.amateras"
   val Name = "gitbucket-gist-plugin"
-  val Version = "3.12.0"
+  val Version = "3.13.0"
   val ScalaVersion = "2.11.6"
 
   lazy val project = Project (