Landscapes

Added 10 new functions:
- AMGM
- Bent Cigar
- Carrom Table
- Chichinadze
- Chung Reynolds
- Cosine Mixture
- Csendes
- Cube
- Damavandi
- Freudenstein Roth

Added the <a href="https://www.sfu.ca/~ssurjano/michal.html">Michalewicz</a> test function to better support <a href="https://github.com/HaaLeo/swarmlib">swarmlib</a> thanks to HaaLeo.

Added 20 new functions:
- Ackley N.2 function: `single_objective.ackley_n2`
- Adjiman function: `single_objective.adjiman`
- Bird function: `single_objective.bird`
- Bohachevsky N.1 function: `single_objective.bohachevsky_n1`
- Bohachevsky N.2 function: `single_objective.bohachevsky_n2`
- Bohachevsky N.3 function: `single_objective.bohachevsky_n3`
- Brent function: `single_objective.brent`
- Brown function: `single_objective.brown`
- Deckkers-Aarts function: `single_objective.deckkers_aart`
- Dixon & Price function: `single_objective.dixon_price`
- Exponential function: `single_objective.exponential`
- Hosaki function: `single_objective.hosaki`
- Keane function: `single_objective.keane`
- Leon function: `single_objective.leon`
- Parsopoulos function: `single_objective.parsopoulos`
- Pen Holder function: `single_objective.pen_holder`
- Plateau function: `single_objective.plateau`
- Qing function: `single_objective.qing`
- Salomon function: `single_objective.salomon`
- Wolfe function: `single_objective.wolfe`

Added the following functions:
- Bartels Conn Function: `single_objective.bartels_conn`
- Colville Function: `single_objective.colville`
- Griewank Function: `single_objective.griewank`
- Rotated Hyper-Ellipsoid: `single_objective.rotated_hyper_ellipsoid`
- Six-Hump Camel: `single_objective.camel_hump_6`
- Step Function: `single_objective.step`
- Sum of Squares: `single_objective.sum_of_squares`
- Trid Function: `single_objective.trid`
- Tripod Function: `single_objective.tripod`
- Zakharov Function: `single_objective.zakharov`

Renamed:
- `single_objective.three_hump_camel()` to `single_objective.camel_hump_3()`