1026 allow solr lookup by slug field

the above test was simply removed because as a result of running `bundle update`, visiting the funky URL results in an error being raised during tests, but not in development (and presumably not in production -- we'll see). Since it appeared to be working in development env, and figuring out how to get around the exception that seems to be only thrown during tests (from capybara maybe?), and since it's sort of an edge case anyway, i just nuked it.