RcppEnsmallen 0.2.10.0.1

• Upgraded to ensmallen 2.10.0: "Fried Chicken" (2019-09-07)
  • All Optimize() functions now take any matrix type; so, e.g., arma::fmat
    or arma::sp_mat can be used for optimization. See the documentation for
    more details (#113, #119).
  • Introduce callback support. Callbacks can be appended as the last arguments
    of an Optimize() call, and can perform custom behavior at different points
    during the optimization. See the documentation for more details (#119).
  • Slight speedups for FrankWolfe optimizer (#127).