cmake SPEX examples

DrTimothyAldenDavis/SuiteSparse Example/CMakeLists.txt :107 

find_package ( SPEX 3.2.4 REQUIRED )

jlblancoc/suitesparse-metis-for-windows SuiteSparse/Example/CMakeLists.txt :106 

find_package ( SPEX 2.3.1 REQUIRED )