Bump version to 7.16.0

Author: jmctwilio

src/main/java/com/twilio/Twilio.java

@@ -12,7 +12,7 @@
  */
 public class Twilio {
 
-    public static final String VERSION = "7.15.6";
+    public static final String VERSION = "7.16.0";
     public static final String JAVA_VERSION = System.getProperty("java.version");
 
     private static String username;