Travis CI: Install required build deps.
Travis CI: Install required build deps.

rgolubtsov/nonlinear-optimization-algorithms-multilang,rgolubtsov/nonlinear-optimization-algorithms-multilang,rgolubtsov/nonlinear-optimization-algorithms-multilang,rgolubtsov/nonlinear-optimization-algorithms-multilang,rgolubtsov/nonlinear-optimization-algorithms-multilang,rgolubtsov/nonlinear-optimization-algorithms-multilang,rgolubtsov/nonlinear-optimization-algorithms-multilang