Precising disk requirements for bosh-cli so that it can be used to deploy CF

To avoid ones that specially create small ubuntu vms to run out of disk space and have to increase their home and /tmp partitions sizes
Adds required properties to Maven plugin settings.
Merge pull request #283 from Orange-OpenSource/bosh-cli-disk-req

Precising disk requirements for bosh-cli so that it can be used to deploy CF
Merge pull request #285 from pivotal/issue-284

Adds required properties to Maven plugin settings.