Connect to s3 on every request.

This will mitigate a lock up that we've seen with module-level connects
elsewhere.
Change the DEFAULT section to the moneypenny section.
Validate message in constant time.
Upload image to S3 in fewer roundtrips.
Use string formatting instead of templates.

This also removes the dependency on babel and gives us greater flexibilty to
change the date subsitution.
Submit a self post if getting the image fails.
Don't run in debug mode.
Don't validate the s3 bucket.

This reduces the permission set required.
Read the entire image into memory.

key.set_contents_from_file() wanted to seek() on the file object which
Response does not implement.
Submit the correct s3 URL.
Log the link to the reddit post.