Fix brew installation failing if formula is already installed. Change-Id: I8b297a7b8ae1cd2e3a34e38f52121f420d5b7651
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.