added Maestrodev's maven puppet module, and used it to install Maven 3.0.5
made mvn_version configurable via hiera, default version is 3.0.5 set in common.yaml, but you can override in local.yaml, if you wish
Merge pull request #26 from hardyoyo/DS-2102-make-maven-version-configurable

DS-2102 make maven version configurable
Update README.md

added mvn_version documentation to README.md (documentation for DS-2102)
Update local.yaml.example

added example setting for mvn_version, as documentation for DS-2102