Update to version 0.3.0
Update to version 0.3.0

- Bumped NIFI_VERSION to 0.3.0
- Added sha1sum check
- Changed mirror to a new destination

GDATAAdvancedAnalytics/docker-nifi,mkobit/docker-nifi,GDATAAdvancedAnalytics/docker-nifi,mkobit/docker-nifi