Add method to map services to json for search
Merge branch 'master' into add_json_search_data
Render json file to back the js search

`python create_pages.py` should now also create `output/search.json`
Better JSON generation

 - Only include data used in search
 - Let the service object deal with which kpi to return
Fix keywords property name
Use simplejson to render Decimal as number in json

Also, in search.json, transactionsPerYear property is now null when not available
Service keywords as a list
Merge pull request #19 from alphagov/add_json_search_data

Add json search data