add --debug=time to scons line in travis

This might help to figure out why builds time out and what parts
of the compilation process are slow.

.travis.yml

@@ -24,7 +24,7 @@ install:
     - sudo apt-get update -qq
     - sudo apt-get install -qq libboost-iostreams-dev libboost-program-options-dev libboost-regex-dev libboost-system-dev libboost-test-dev libcairo2-dev libfribidi-dev libpango1.0-dev libsdl-image1.2-dev libsdl-mixer1.2-dev libsdl-net1.2-dev libsdl-ttf2.0-dev
 script: 
-    - scons cxxtool=$CXX strict=$STRICT_COMPILATION $TARGETS
+    - scons cxxtool=$CXX --debug=time strict=$STRICT_COMPILATION $TARGETS
     - "export DISPLAY=:99.0"
     - "sh -e /etc/init.d/xvfb start"
     - if [[ "$CPP_TESTS" = true ]]; then ./test_wrapper.sh; fi