Add data as .geojson

To test [this
feature](https://github.com/blog/1528-there-s-a-map-for-that)
Merge branch 'master' into geojson
Update geojson

Now includes renamed fields `text_on_sign` and `text_below_sign
Add geojson as resource to datapackage.json
Use web instead of url for code reference
Use integer for cartodb_id
Use datetime for created/updated_at
Merge branch 'master' into geojson

Conflicts:
	datapackage.json
Last update from CartoDB
Format geojson with indentation and multiple lines
Verify syntax
Correct syntax for strings
Correct string syntax for geometry
Validate geojson

Geojson now validates! http://geojsonlint.com/
Remove created_at / updated_at

ALL changes can now be tracked with git
Correct indentation of properties
Uncollapse coordinates
Sort geojson on cartodb_id
Sort properties
Rename cartodb_id to id