Not checking validations on attachments save for paperclip 4.0

- In the new version of paperclip content spoofing validation interferes with uploading whatever you want
- Additionally added I18n translation and call to required paperclip validation
- Adding arel and tzinfo because they were expected to resolve some dependency
Merge pull request #313 from ninjapanzer/ninjapanzer/fix_s3_paperclip

Issues with S3 and new version of Paperclip validations