Empty commit for create artist branch.
Add a link to a new artist from the dashboard.

I like writing tests like these, even though they seem kinda trivial, because
if I do visual refactoring of the HTML/CSS/JS later, I can ensure that I don't
break anything.

I've also moved the `sign_in` helper into a more global scope, as an increasing
number of tests will use it.

Finally, you'll notice that I use `only` in my routes more than most people.
It's true that those will just be a 404 if they're not defined, but I like
being extra explicit here. For example, `rake routes` would show waaaay more
routes than I actually use. Routes are an interface into your application: you
should limit them as much as possible.
Create a new artist.

I looooove `assert_difference`.

Note that this isn't perfect yet: I don't test that it's associated
with the correct shop. But at least I'm making them!

The rest of this is pretty boring, bread and butter kinds of things.
Nothing particularly exciting.
Show the artists on the shop dashboard.

The only really interesting change here is that we make `sign_in` now
return a reference to the shop.
Ensure we associate an artist with a shop

I am not happy about this test, but I'm stumped on how to do
it better. At least I can leave myself a note for if/when this breaks
in the future.
Merge pull request #13 from artisan-tattoo/create_artist

Create a new artist