Add conjugate gradient descent

CMakeLists.txt

apps/plots.py

optimization/objectives/rosenbrock.h

optimization/objectives/samples.h

optimization/optimizers/CMakeLists.txt

...tion/optimizers/conjugate_gradient_descent/CMakeLists.txt

...s/conjugate_gradient_descent/conjugate_gradient_descent.h

...njugate_gradient_descent/conjugate_gradient_descent_log.h

...njugate_gradient_descent/conjugate_gradient_descent_vis.h

optimization/optimizers/conjugate_gradient_descent/main.cpp

optimization/optimizers/gradient_descent/main.cpp

optimization/optimizers/line_search/bracket.h

optimization/optimizers/line_search/brent.h

optimization/optimizers/line_search/golden_section.h

optimization/optimizers/line_search/line_objective.h

optimization/optimizers/nelder_mead/main.cpp

optimization/optimizers/nelder_mead/nelder_mead.h

test/CMakeLists.txt

test/main.cpp

test/optimizers/line_search/bracket.cpp