Make Redis spec succeed independent of order

    $ bundle exec rspec --order random:13210

        1) Stoplight::DataStore::Redis behaves like a data store should eql
         Failure/Error: it { expect(data_store.names).to eql([]) }

           expected: []
                got: ["4874faf313fd4df6632263980c5ac720", "27de924568ccd6e64fdf71f0f281c87a"]

           (compared using eql?)
Add an icon to the readme