Assert that commons-io signatures for known versions produce no warning

Author: uschindler

src/test/antunit/TestCommonsIOSignatures.xml

@@ -34,6 +34,7 @@
     <ivy:cachepath organisation="commons-io" module="commons-io" revision="${commons-io-version}"
       inline="true" conf="master" type="jar" pathid="commons-io.classpath" log="${ivy.logging}"/> 
     <forbiddenapis bundledSignatures="${commons-io-signature}" ignoreEmptyFileset="true" classpathref="commons-io.classpath" targetVersion="${jdk.version}"/>
+    <au:assertLogDoesntContain level="warning" text="choosing next lower available signature"/> 
   </target>
 
   <target name="testVersionDowngradeAndEquivalence">