fix #59, can't EXCLUDE_FROM_ALL the test directory
fix #59, can't EXCLUDE_FROM_ALL the test directory

mjbshaw/Eigen,madlib/eigen_backup,rotorliu/eigen,rotorliu/eigen,mjbshaw/Eigen,madlib/eigen_backup,madlib/eigen_backup,rotorliu/eigen,rotorliu/eigen,mjbshaw/Eigen,madlib/eigen_backup,mjbshaw/Eigen