Merge branch 'v5.1'

[fix] PyPi topic

Improved benchmarking facility

CSV file for every pair

Removed unused code

Dumping Pareto populations

PIs are computed at the end of the benchmark

Always save minimization history

Consistent .npz files keys

More logging in benchmark

Standardized filenames

Default PIs

Bumped version

Changelog for v4

Better algorithm description in benchmarks

See documentation of `Benchmark.__init__`.

Multivariate Gaussian noise

Packaging