Upgrade ecj to 3.20.0

Change-Id: Ic72d05567d4c90f3d720a166afe99148fb003592
Signed-off-by: David Pursehouse <david.pursehouse@gmail.com>

pom.xml

@@ -928,7 +928,7 @@
               <dependency>
                 <groupId>org.eclipse.jdt</groupId>
                 <artifactId>ecj</artifactId>
-                <version>3.19.0</version>
+                <version>3.20.0</version>
               </dependency>
             </dependencies>
           </plugin>