PoC object storage

#355 (closed)

Add objectstorage package using minio's Go SDK. Hardcoding a lookup as if returned from the Rails API. Can currently serve any files within a specified bucket. Still some things to work out. I've added some TODOs but I'll consolidate them when a get some more time.

• serve individual files
• serve from a .zip file and cache in memory
• add some benchmarks?