Update Version.java to 7.0.0.

Author: cbeust

src/main/java/org/testng/internal/Version.java

@@ -2,7 +2,7 @@
 
 public class Version {
 
-  public static final String VERSION = "DEV-SNAPSHOT";
+  public static final String VERSION = "7.0.0";
 
   public static String getVersionString() {
     return VERSION;