Added basic month/year filtering to stockings

This has a failing test.  I'm opening the pull request to discuss it.  I've added a select to the page and its onchange fires javascript to submit the form.  However, I don't think rspec understands this and so it may not be waiting for the page to reload before looking for last month's stocking.  Thoughts?
Not happy with this case statement, but not sure how to feed the selected value into the scopes