Bump version to 2.4.0

Release with minor bump as Proguard default version has changed.

Author: lasselindqvist

pom.xml

@@ -15,7 +15,7 @@
 	<groupId>com.github.wvengen</groupId>
 	<artifactId>proguard-maven-plugin</artifactId>
 	<name>proguard-maven-plugin</name>
-	<version>2.3.2-SNAPSHOT</version>
+	<version>2.4.0</version>
 	<packaging>maven-plugin</packaging>
 
 	<description>Maven 3 Plugin for ProGuard</description>