Adapted the determinant test for rank 1 matrices with zero determinant.
Adapted the determinant test for rank 1 matrices with zero determinant.

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