Add rspec tasks to Rakefile
Rescue Rails load errors in s3direct.

I'm not sure the better way to deal with this yet.  We didn't include
Rails even as a dev dependency so couldn't even run the specs.  Just
rescuing it for now so we can run specs.
Allow options to pass to UploadRequest.new

If we want to upload a randomized filename from a uuid, but have
the browser able to download the attachment with the real filename
we need to be able to pass an attachment filename for content
disposition use.

Also note that later these options can be used to pass aws acl
if we want to upload private files.
Merge 'bem-optional_content_disposition_filename'