v6.5.0

Reuse MongoDB options class from mongodb-download (#56)
Allow download options to be passed in as env vars (#55)

v6.4.0

Upgrade mongodb-download to 2.2.7 with support for more OSes and mongodb versions (db4678b)
Remove mocha from dependencies (591ab74)
Add control over mongodb-download options (#51)
Implement MongoDBHelper.{stop(), kill()} (#49)