make cmake builds tests when they are enabled in travis

.travis.yml

@@ -61,7 +61,7 @@ script:
     - ./utils/travis/utf8_bom_dog.sh
     - $CXX --version
     - if [ "$USE_CMAKE" = false ]; then scons cxxtool=$CXX --debug=time build=release extra_flags_config=-pipe extra_flags_release="$EXTRA_FLAGS_RELEASE" strict=$STRICT_COMPILATION $TARGETS cxx_std=$CXXSTD nls=$NLS jobs=2; fi
-    - if [ "$USE_CMAKE" = true ]; then cmake . -DENABLE_STRICT_COMPILATION=$STRICT_COMPILATION -DENABLE_NLS=$NLS && make -j2; fi
+    - if [ "$USE_CMAKE" = true ]; then cmake . -DENABLE_STRICT_COMPILATION=$STRICT_COMPILATION -DENABLE_NLS=$NLS -DENABLE_TESTS=$CPP_TESTS && make -j2; fi
     - "export DISPLAY=:99.0"
     - "/sbin/start-stop-daemon --start --quiet --pidfile /tmp/custom_xvfb_99.pid --make-pidfile --background --exec /usr/bin/Xvfb -- :99 -ac -screen 0 1024x768x24"
     - if [ "$CPP_TESTS" = true ]; then ./utils/travis/test_wrapper.sh; fi