Revert "remove cmake workaround"

This reverts commit 6bc758e.

Author: lkeegan

build.sh

@@ -32,6 +32,8 @@ echo "VTK_VERSION: ${VTK_VERSION}"
 echo "SCOTCH_VERSION: ${SCOTCH_VERSION}"
 echo "NLOPT_VERSION: ${NLOPT_VERSION}"
 
+export "CMAKE_POLICY_VERSION_MINIMUM=3.5"
+
 NPROCS=4
 echo "NPROCS: ${NPROCS}"
 echo "PATH: ${PATH}"