fixed file location of update image template due to change in resources prefix (#35)

Author: ddsharpe

imagetool/src/main/java/com/oracle/weblogic/imagetool/cli/menu/UpdateImage.java

@@ -162,7 +162,7 @@ public CommandResponse call() throws Exception {
             cmdBuilder.addAll(handlePatchFiles(tmpDir, tmpPatchesDir));
 
             // create dockerfile
-            Utils.writeDockerfile(tmpDirPath + File.separator + "Dockerfile", "/docker-files/Update_Image.mustache", dockerfileOptions);
+            Utils.writeDockerfile(tmpDirPath + File.separator + "Dockerfile", "Update_Image.mustache", dockerfileOptions);
 
             // add directory to pass the context
             cmdBuilder.add(tmpDirPath);