Sets MongoDB to use a smaller default file size

[Zhigalov]

When I run mongo as a service in drone:

pipeline
  ...
services:
  database:
    image: tutum/mongodb
    pull: true
    environment:
      - AUTH=no

I catch error:

2016-12-01T08:16:50.911+0000 [initandlisten] ERROR: Insufficient free space for journal files
0s
12
2016-12-01T08:16:50.911+0000 [initandlisten] Please make at least 3379MB available in /data/db/journal or use --smallfiles