Remove optimization build flags on Travis-CI to speed up the build

CI/before_script.linux.sh

@@ -5,4 +5,4 @@ mkdir build
 cd build
 export CODE_COVERAGE=1
 if [ "${CC}" = "clang" ]; then export CODE_COVERAGE=0; fi
-${ANALYZE}cmake .. -DBUILD_WITH_CODE_COVERAGE=${CODE_COVERAGE} -DBUILD_UNITTESTS=1 -DCMAKE_INSTALL_PREFIX=/usr -DBINDIR=/usr/games  -DCMAKE_BUILD_TYPE="RelWithDebInfo" -DUSE_SYSTEM_TINYXML=TRUE
+${ANALYZE}cmake .. -DBUILD_WITH_CODE_COVERAGE=${CODE_COVERAGE} -DBUILD_UNITTESTS=1 -DCMAKE_INSTALL_PREFIX=/usr -DBINDIR=/usr/games  -DCMAKE_BUILD_TYPE="None" -DUSE_SYSTEM_TINYXML=TRUE