Mark mojo as not requiring a project.
Correct unit is Gigabyte, not Terabyte (1000 x* Gb)
Merge pull request #1 from Vlatombe/dontRequireProject

Mark mojo as not requiring a project.
Merge pull request #2 from Vlatombe/fixUnits

Correct unit is Gigabyte, not Terabyte (1000 x* Gb)
Unit conversion corrected.
New Version that correctly shows reclaimed space and can be called by
Maven without Project.

Contributed by Vincent Latombe