Bump to 1.5.0 to support GitBucket 4.23.0

Author: takezoe

Diff for: README.md

@@ -4,7 +4,8 @@ This plug-in provides notifications feature on GitBucket.
 
 Plugin version | GitBucket version
 :--------------|:--------------------
-1.4.0          | 4.19.0
+1.5.x          | 4.23.0
+1.4.x          | 4.19.x - 4.22.x
 1.2.x, 1.3.x   | 4.17.x - 4.18.x
 1.1.x          | 4.16.x
 1.0.x          | 4.15.x

Diff for: build.sbt

@@ -1,5 +1,5 @@
 name := "gitbucket-notifications-plugin"
 organization := "io.github.gitbucket"
-version := "1.4.0"
+version := "1.5.0"
 scalaVersion := "2.12.4"
-gitbucketVersion := "4.19.0"
+gitbucketVersion := "4.23.0"

Diff for: src/main/scala/Plugin.scala

@@ -27,7 +27,8 @@ class Plugin extends gitbucket.core.plugin.Plugin {
     new Version("1.3.0",
       new LiquibaseMigration("update/gitbucket-notifications_1.3.xml")
     ),
-    new Version("1.4.0")
+    new Version("1.4.0"),
+    new Version("1.5.0")
   )
 
   override val controllers = Seq(