update to node-mapnik 1.3.x - refs mapnik/node-mapnik#209
bump package.json
use node-mapnik@1.3.0-alpha2
node-mapnik@1.3.0-alpha3
npm publish is borked, switch to github
bump to node-mapnik@1.3.0-alpha4
use node-mapnik@1.3.0
Merge pull request #32 from mapbox/node-mapnik-1.3

Update to node-mapnik 1.3.x - refs mapnik/node-mapnik#209