Add utility to find a free port

[tntim96]

No description provided.

[Yasir761]

@tntim96 Can you please suggest some more information?

[tntim96]

Sure @Yasir761 . Basically something like this: http://svn.apache.org/viewvc/camel/trunk/components/camel-test/src/main/java/org/apache/camel/test/AvailablePortFinder.java?view=markup#l130

This is so wrapping code in our CI environment can ensure JSCover is running on an unused port. The method signature can be the same as in that sample I think.