Remove print statements for boto warning

[denibertovic]

views/s3.py should remove print statements warning that boto is not installed. This should use a proper logger so that this can be silenced.

Or remove altogether. I'm using the local backend and getting these warnings for some reason.

[skoczen]

Seems reasonable to me - mind submitting a quick PR?

[denibertovic]

will do.

[skoczen]

Just a ping on this - if you've got time for the PR, it's still welcome!