Initialize aws with credentials for dev environment.
user
```ruby
require 'aws-sdk'

AWS.config(
  access_key_id:     Rails.application.secrets.aws_access_key_id,
  secret_access_key: Rails.application.secrets.aws_secret_access_key
)

# S3_BUCKET = AWS::S3.new.buckets[Rails.application.secrets.s3_bucket_name]
```
assistant