Fix paperclip s3 config

[NikitaAvvakumov]

Attempting to fix S3 config for Paperclip:

• s3_region must be specified under s3_credentials under config.paperclip_defaults in config/environments/.rb

• production S3 bucket is in Ireland (eu-west-1), while dev & staging are in us-east-1. Hoping that the production error is due to this and can be resolved by configuring the s3_host_name option for Paperclip - have set S3_HOST_NAME Heroku ENV to s3.amazonaws.com for dev & staging, osra-prod.s3.amazonaws.com for production (as per error response from S3 in the screenshot)

[coveralls]

Coverage remained the same at 99.559% when pulling 620803674916417dfa7a481938a3187ce9230b3b on NikitaAvvakumov:fix-paperclip-s3-config into a7b11e4f0d60c81d63fb33f02de9469de1a8c21d on AgileVentures:develop.