Update README to use aws-sdk gem rather than aws-s3
Merge pull request #27 from kpopper/develop

Update README to use aws-sdk gem rather than aws-s3
Add pullrequested commits
[Fix query for refreshing attachments. Mongoid query (mschulkind)] : https://github.com/mschulkind/mongoid-paperclip/commit/e6e911036b96e8718bf000028d226e4b2d3df85b
[Really good for recent Mongoid 3 compliance] : https://github.com/meskyanichi/mongoid-paperclip/pull/31/commits
Upgrade the gem version to "0.0.9".
Merge branch 'master' of github.com:fenicks/mongoid-paperclip