Bump to 1.3.0

Author: shimamoto

build.sbt

@@ -1,6 +1,6 @@
 val Organization = "io.github.gitbucket"
 val ProjectName = "gitbucket-notifications-plugin"
-val ProjectVersion = "1.2.0"
+val ProjectVersion = "1.3.0"
 val GitBucketVersion = Option(System.getProperty("gitbucket.version")).getOrElse("4.17.0")
 
 name := ProjectName