Revert "ensure c++ 11 is used"
Revert "ensure c++ 11 is used"

This reverts commit 0c242fa1224da96456c8525f61f3ddcad052d172.

The cluster's gcc does not have this option.

uwsampa/accept,jck/accept,jck/accept,jck/accept,uwsampa/accept,jck/accept,uwsampa/accept,uwsampa/accept