Give SBT a bit more memory so it can do a update / compile / test in one JVM

sbt/sbt

@@ -4,4 +4,4 @@ if [ "$MESOS_HOME" != "" ]; then
   EXTRA_ARGS="-Djava.library.path=$MESOS_HOME/lib/java"
 fi
 export SPARK_HOME=$(cd "$(dirname $0)/.."; pwd)
-java -Xmx700M $EXTRA_ARGS -jar $SPARK_HOME/sbt/sbt-launch-*.jar "$@"
+java -Xmx800M -XX:MaxPermSize=150m $EXTRA_ARGS -jar $SPARK_HOME/sbt/sbt-launch-*.jar "$@"