In 06-volumes use --mount instead of --volume

[samuel-enderwitz-eficode]

Regarding to https://docs.docker.com/storage/bind-mounts/#choose-the--v-or---mount-flag one should use --mount to deal with docker volumes.
I propose to change the kata to use --mount instead of --volume.

[atombrella]

@samuel-enderwitz-eficode Feel free to open a PR :) However, -v is simpler than --mount.