Merge pull request #24 from sadfuzzy/master

Add support for placing files in folders.
Ignoring directories on rake test to upload files

fix ka8725/redmine_s3#20
Merge pull request #25 from marlonandrade/master

Ignoring directories on rake test to upload files
Adding bundle install as a step for installation

Redmine installation plugin tutorial doesn't say anything about those
gem dependencies, so I think the plugin should tell the users to do
that
Being more explicit on `bundle install` step

Explaining better why a `bundle install` might be necessary.

Because this plugin requires `aws-sdk`, a redmine instalation that is already running should install it.

If all dependencies are already installed a new `bundle install` would install anything else.
Merge pull request #26 from marlonandrade/master

Adding bundle install as a step for installation
Update for redmine 2.6.