Manuscript and PTB Dream challenge release

This is the release of MaLiAmPi to correspond with the 2021 / 2022 preterm birth DREAM challenge and associated methods manuscript.

What's Changed

• New dada2 and unit tests by @jgolob in #13
• Updated to new version of vsearch by @jgolob in #15

Full Changelog: v3...v3.5.0