[WIP] Feature/populate

[widnyana]

add populate mechanism

todo:

• [x] fetch starred repo
• [x] save to boltdb
• [ ] add api to trigger populate
• [ ] figure out, is it posible to repopulate starred repo withoud overwriting old data
• [ ] clean up before merge

[widnyana]

seems promising: https://github.com/asdine/storm