Add catches_strings test to test throws char * typemap

Examples/test-suite/ruby/catches_strings_runme.rb

@@ -0,0 +1,18 @@
+#!/usr/bin/env ruby
+
+require 'swig_assert'
+
+require 'catches_strings'
+
+exception_thrown = false
+begin
+  Catches_strings::StringsThrower.charstring()
+rescue RuntimeError => e
+  if (!e.to_s.include? "charstring message")
+    raise RuntimeError, "incorrect exception message: #{e.to_s}"
+  end
+  exception_thrown = true
+end
+if (!exception_thrown)
+  raise RuntimeError, "Should have thrown an exception"
+end