TravisCI: also test CMake build out of source

.travis.sh

@@ -48,6 +48,13 @@ elif [[ ${MODE} = cmake ]]; then
     make all test
     make DESTDIR="${PWD}"/ROOT install
     ( cd ROOT/ && find | sort )
+elif [[ ${MODE} = cmake-oos ]]; then
+    mkdir build
+    cd build
+    cmake ..
+    make all test
+    make DESTDIR="${PWD}"/ROOT install
+    ( cd ROOT/ && find | sort )
 else
     ./qa.sh "${MODE}"
 fi

.travis.yml

@@ -10,6 +10,7 @@ env:
   matrix:
     - MODE=address
     - MODE=cmake
+    - MODE=cmake-oos
     - MODE=distcheck
     - MODE=lib-coverage