Added aws credz to config
Configure fog directory
Warn if can't save screenshot

This way the message in the delayed jobs table isn't something useless about
AWS if we can't communicate with s3 for some reason.
Get the keyz in the config
Not SECRET_ACCESS_KEY_ID
Merge pull request #13 from NGPVAN/DIGITAL-3184-use-s3-credz

DIGITAL-3184 use s3 credz