Release v0.1.8

What's Changed

• Feat phate kernel by @GregorLueg in #14
• Feat phate markov by @GregorLueg in #15
• Fix eigenpair by @GregorLueg in #18
• Feat better umap optim by @GregorLueg in #19
• Feat phate finalisation by @GregorLueg in #20
• Phate restructure by @GregorLueg in #21
• Feat phate by @GregorLueg in #22

Full Changelog: v0.1.7...v0.1.8