Fix include directories to include contrib (#78, thanks @musicinmybrain)

Author: martinmoene

contrib/CMakeLists.txt

@@ -3,6 +3,8 @@
 # Distributed under the Boost Software License, Version 1.0. (See accompanying
 # file LICENSE.txt or copy at http://www.boost.org/LICENSE_1_0.txt)
 
+include_directories( "../contrib" )
+
 add_subdirectory( lest_expect_abort  )
 add_subdirectory( lest_expect_assert )