Added reference to Kelley in solvers.steepest
Added reference to Kelley in solvers.steepest

Forgot before. Reference to Iterative Methods of Optimization.

drandykass/fatiando,victortxa/fatiando,victortxa/fatiando,eusoubrasileiro/fatiando,eusoubrasileiro/fatiando,eusoubrasileiro/fatiando_seismic,drandykass/fatiando,rafaelmds/fatiando,cmeessen/fatiando,santis19/fatiando,cmeessen/fatiando,rafaelmds/fatiando,fatiando/fatiando,santis19/fatiando,eusoubrasileiro/fatiando_seismic,fatiando/fatiando,mtb-za/fatiando,eusoubrasileiro/fatiando,mtb-za/fatiando