upgrade to storages=1.1.6, boto 2.7.0 (#1923)
remove storages response_headers() patch (#1923)

We still need this patch, we are just doing via monkeypatching instead
of patching the file on disk (thanks to @jrbl).
videocheck, print id and filename to help debugging
Merge pull request #1934 from Stanford-Online/sef-1923-boto-storages-versions

Upgrade boto and storages versions (#1923) to master