added sonatype repos to pom.
added sonatype repos to pom.

digitalreasoning/factorie-scala-210,strubell/factorie,factorie/factorie,patverga/factorie,melisabok/factorie,Craigacp/factorie,malcolmgreaves/factorie,zxsted/factorie,joprice/factorie,hlin117/factorie,pogren-oracle/factorie,asubbaswamy/factorie