checker for .dockerignore and .gcloudignore

make sure following are ignored
- [ ] .git
- [ ] .svn
- [ ] *.gpg
- [ ] *.pfx
- [ ] *.pem
- [ ] *.cer
- [ ] *.cert
- [ ] *.p12
- [ ] *.key
- [ ] .env
- [ ] docker-compose.override.yml

PS. error only if offensive file found.