CI: more debugging due to disk-space problems

ci/travis-continuous.sh

@@ -15,9 +15,11 @@ cd $BUILDDIR || exit 1
 echo "###"
 echo "### cmake $CMAKE_ARGS $SRCDIR"
 echo "###"
+df -h
 cmake $CMAKE_ARGS $SRCDIR || { echo "! CMake failed" ; exit 1 ; }
 
 echo -e "###\n### make\n###"
+df -h
 make -j2 || { make -j1 VERBOSE=1 ; echo "! Make failed" ; exit 1 ; }
 
 echo -e "###\n### make install\n###"