Use bio crate to represent genomes

[sebschmi]

Apparently the bio crate contains all the functionality to store sequences compactly, so no reason to do that myself.

Clarification: The compact-genome crate should stay, as it contains the traits for genomes, but it should be enhanced with a compact representation using bio, as well as an abstraction from concrete alphabets using bio.

• make plan
• add SimpleGenome, CompactGenome and DefaultGenome type aliases where: Simple is the fastest, compact the smallest, and default a good compromise between both.