Should accept URL w/o http[s]:// on front

[davearonson]

As a lazy user,
I want to omit the http:// or https:// on the front of the URL,
So I can type less.

When I submit a URL for a Github PR, without the protocol,
Then it should be successfully saved,
And when I click on it in the list,
Then it should take me to the correct place.

[davearonson]

Done. Didn't copy the above acceptance-test in; this was doable with a low-level unit test.