Fix rotation_test.cc to work with older versions of Eigen Change-Id: I699e4b45f9a1cc09e72f8140e67c800c3bcef8e0
Ceres Solver is an open source C++ library for modeling and solving large, complicated optimization problems. It is a feature rich, mature and performant library which has been used in production at Google since 2010. Ceres Solver can solve two kinds of problems.
Please see ceres-solver.org for more information.