Update Pom.xml

This code is forked from https://github.com/DFectuoso/LiftSquareGame .
We have made some changes in  pom.xml . Since http://scala-tools.org/ is no 
longer serving jars , so we have changed url to 
https://oss.sonatype.org/content/groups/scala-tools/  .




There is no Lift version 1.1-SNAPSHOT available so , 
we have changed Lift version to 1.1-M8 .