Include 'pushed_at' value in project details.
Include 'pushed_at' value in project details.

Fixes https://github.com/open-city/civic-json-worker/issues/9

chihacknight/civic-json-worker,EvanHahn/civic-json-worker,open-city/civic-json-worker,MaxPresman/cfapi,smalley/cfapi,codeforamerica/cfapi,MaxPresman/cfapi,smalley/cfapi,EvanHahn/civic-json-worker,smalley/cfapi,codeforamerica/cfapi,0111001101111010/cfapi,0111001101111010/cfapi,MaxPresman/cfapi