Create auto-generated stats at the repository level

[noahsprent]

Following on from #39, in which package-level stats were autogenerated, we need to also generate these stats at the repository level. This will necessarily have duplicates that get unioned. These stats should include:

• Number of unique parts
• Classes of parts
• Number of plasmids used
• Number of part/backbone combinations (i.e., wells required)
• Issues in the package