0.3.1

What's Changed

• [FEATURE] add lexicographic rank by @VascoSch92 in #111
• [FIX] Typos in class methods of class Permutation by @VascoSch92 in #112
• [FEATURE] Lehmer code of a permutation by @VascoSch92 in #113
• [RELEASE] 0.3.1 by @VascoSch92 in #114

Full Changelog: 0.3.0...0.3.1