Get tags back in sync: upversion to 1.0.4

The tag for 1.0.3 is pointing at a version of the code which reports to
be 1.0.2.

As far as I can see the best way to resolve is to upversion and add a
new tag (rather than overwrite the existing tag)
Merge pull request #18 from scraperwiki/get-tags-back-in-sync

Get tags back in sync: upversion to 1.0.4