Updated doc's maven version to 1.48
Updated doc's maven version to 1.48

The documentation's example Maven `<dependency>` declaration says to use version 1.30, but according to GitHub's "Releases" tab, it looks like v1.48 has been released.
selliera/jcommander,selliera/jcommander,VikingDen/jcommander,winndows/jcommander,cbeust/jcommander,selliera/jcommander,cbeust/jcommander,cbeust/jcommander