running mvn cargo:start does not redeploy newer war files

steps to reproduce:

• run mvn cargo:start on a war project with an existing tomcat installation
• the war file is copied into the tomcat/webapps directory
• shutdown cargo
• run mvn install to create new war file (probably make some changes to notice the change)
• run mvn cargo:start
• cargo fails to copy the new war file into tomcat and so it's still running the old code.

The only workaround I know is to always run mvn clean before running cargo.