External sql import

[pquerner]

Here [1] you force the .sql file created / downloaded from vinais compressed sample-data project.
It would be better if thats only a fallback solution and you could overwrite this.

Reason: you could use this project to test some external app which utilizes magento but needs project data (ie. products).

[1] https://github.com/andreaskoch/dockerized-magento/blob/master/config/installer/bin/install.sh#L123