Limit `cleanair-otp-data` bucket version history

[rachelekm]

As a follow up to #1403, we've turned on versioning to the cleanair-otp-data S3 bucket which will hold our source data and graph objects created each month. These files are heavy (Graph.obj is ~1 GB, the largest changing feed file is cac.pbf at ~200MB) and we don't need every past version, just the last month or two in case we need to revert or reference valid sources. To conserve costs, limit the bucket version history. Should look into S3 lifecycle management to achieve this.