Fetch from branch v4 in Spark EC2 script.
[SPARK-3856][MLLIB] use norm operator after breeze 0.10 upgrade

Got warning msg:

~~~
[warn] /Users/meng/src/spark/mllib/src/main/scala/org/apache/spark/mllib/feature/Normalizer.scala:50: method norm in trait NumericOps is deprecated: Use norm(XXX) instead of XXX.norm
[warn]     var norm = vector.toBreeze.norm(p)
~~~

dbtsai

Author: Xiangrui Meng <meng@databricks.com>

Closes #2718 from mengxr/SPARK-3856 and squashes the following commits:

4f38169 [Xiangrui Meng] use norm operator