Fix ctest paths

Author: zbeekman

.travis.yml

@@ -153,8 +153,8 @@ script:
       ln -fs "$(which g++-6)" "$HOME/bin/g++"
       export PATH="$PATH:$HOME/bin"
       ./install.sh --yes-to-all -i "$HOME/opt/opencoarrays" -j 4 -f "$HOME/bin/gfortran" -c "$HOME/bin/gcc" -C "$HOME/bin/g++"
-      cd prerequisites/builds/opencoarrays*
-      ctest --output-on-failure
+      cd prerequisites/builds/opencoarrays/*
+      ../../../installations/cmake/*/bin/ctest --output-on-failure
       cd -
     else
       mkdir cmake-build