Add Supports for Exports Read/Writing From S3 Buckets

[1nv8rzim]

Purpose

One of the things I have been working towards is a stateless deploy of yeti in order to deploy several replicas of the celery runner and api containers. The biggest blocker for this is that a shared volumes between several containers is an anti-pattern and not supported on the cluster I am deploying to.

This PR introduces the ability to replaces this shared volume with an S3 Complaint Bucket

Changes

• When system.export_path is prefixed with s3:// it will attempt to use S3 as the storage mediums for exports
  • Example: Setting system.export_path to s3://bucket_name would use bucket_name for storage of export task results
• Celery Runner can now upload results export tasks to an s3 compliant bucket
• API is able to read results of export task from an s3 compliant bucket
• Credentials and configuration for s3 buckets access should be injected by environment variables

[1nv8rzim]

This works; I am drafting a more generalized approach here so that this same thing can be extended past s3 in the future