Visualization and code linting

This release introduces a lot of renaming. It also correct bugs introduced in alpha version v0.3.0. We ultimately deleted the built-in PSO.

Added

• The bounding_box method of geometry allow to compute the bounding box of a finite set of 2D points.
• You can now customize colors of linkage's bars with the COLOR_SWITCHER variable of visualizer.py.
• movement_bounding_box in visualizer.py to get the bounding box of multiple loci.
• parameters is optional in trials_and_errors_optimization (former exhaustive_optimization)
• pylinkage/tests/test_optimizer.py for testing the optimizers, but it is a bit ugly as for now.

Fixed

• set_num_constraints in Linkage was misbehaving due to update 0.3.0.
• Cost history is no longer plotted automatically after a PSO.

Changed

• exhaustive_optimization is now known as trials_and_errors_optimizattion.
• Axis on linkage visualization are now named "x" and "y", and no longer "Points abcsices" and "Ordinates".
• A default view of the linkage is displayed in plot_static_linkage.
• Default padding in linkage representation was changed from an absolute value of 0.5 to a relative 20%.
• Static view of linkage is now aligned with its kinematic one.
• get_pos method of Linkage is now known as get_coords for consistency.
• Parameters renamed, reorganized and removed in particle_swarm_optimization to align to PySwarms.
• README.md updated consequently to the changes.

Removed

• Legacy built-in Particle Swarm Optimization, to avoid confusions.
• We do no longer show a default legend on static representation.

Security

• Flake8 validation in tox.ini