Bump sprockets from 3.3.5 to 3.7.2
Bump sprockets from 3.3.5 to 3.7.2

Bumps [sprockets](http://getsprockets.org/) from 3.3.5 to 3.7.2.

Signed-off-by: dependabot[bot] <5bdcd3c0d4d24ae3e71b3b452a024c6324c7e4bb@github.com>
akinom/dspace-rails,akinom/dspace-rails,akinom/dspace-rails