Upgrade the release to the latest version

Author: R. Tyler Croy

build.gradle

@@ -15,7 +15,7 @@ buildscript {
 apply plugin: 'idea'
 
 group = 'com.github.jruby-gradle'
-version = '1.3.0'
+version = '1.3.1'
 defaultTasks 'check', 'assemble'
 
 if (!releaseBuild) {

gradle.properties

@@ -8,6 +8,6 @@ releaseBuild=false
 
 targetCompatibility=1.7
 sourceCompatibility=1.7
-jrubyVersion=9.1.2.0
+jrubyVersion=9.1.3.0
 jettyVersion=9.2.12.v20150709
 rubygemsProxy=http://rubygems.lasagna.io/proxy/maven/releases