Update run-example

Old code can only be ran under spark_home and use "bin/run-example".
 Error "./run-example: line 55: ./bin/spark-submit: No such file or directory" appears when running in other place. So change this

Author: maji2014 <maji3@asiainfo-linkage.com>

Closes #1011 from maji2014/master and squashes the following commits:

2cc1af6 [maji2014] Update run-example

Closes #988.