add mongodb configs and Image model
add mgo.DialInfo to db/config
Merge pull request #3 from ciela/connect_db

Connect db
implement drawLGTM method beta
implement drawLGTM in several
move existing draw methods as test
add a test lgtm image
modify test lgtm image
overlay LGTM default image
Delete app/util/ and apply animation GIF almost completely
Delete app/util/ and apply animation GIF almost completely
Revert upload S3 flow to non-goroutine
Refactor drawLGTMWithPaletted
Merge conflicts