Added clang & OS X to .travis
diff --git a/CMakeLists.txt b/CMakeLists.txt
index 5f3da26..d6a9704 100644
--- a/CMakeLists.txt
+++ b/CMakeLists.txt
@@ -74,9 +74,12 @@
 if(APPLE)
   set(CMAKE_CXX_FLAGS
     "${CMAKE_CXX_FLAGS} -std=c++11 -stdlib=libc++ -Wall -pedantic -Werror -Wextra")
-elseif(CMAKE_COMPILER_IS_GNUCXX OR "${CMAKE_CXX_COMPILER_ID}" MATCHES "Clang")
+elseif(CMAKE_COMPILER_IS_GNUCXX)
   set(CMAKE_CXX_FLAGS
     "${CMAKE_CXX_FLAGS} -std=c++0x -Wall -pedantic -Werror -Wextra")
+elseif("${CMAKE_CXX_COMPILER_ID}" MATCHES "Clang")
+  set(CMAKE_CXX_FLAGS
+    "${CMAKE_CXX_FLAGS} -std=c++0x -stdlib=libc++ -Wall -pedantic -Werror -Wextra")
 endif()
 
 if(FLATBUFFERS_CODE_COVERAGE)