Welcome Andrew Musselman as new comitter

Hi,

this is to announce that the Project Management Committee (PMC) for
Apache Mahout has asked Andrew Musselman to become committer and we are
pleased to announce that he has accepted.

Being a committer enables easier contribution to the project since in
addition to posting patches on JIRA it also gives write access to the
code repository. That also means that now we have yet another person who
can commit patches submitted by others to our repo *wink*

Andrew, we look forward to working with you in the future. Welcome! It
would be great if you could introduce yourself with a few words :)

Sebastian