Minor Edit in the programming guide

[Muttineni, Vinay]

Hey guys,
In the Spark 1.3.0 documentation provided here, 
http://spark.apache.org/docs/latest/sql-programming-guide.html ,
Under the "Programmatically Specifying the Schema" section , it's mentioned 
that SQL data types are in the following package org.apache.spark.sql, but I 
guess it has changed to org.apache.spark.sql.types
Great work with the Data Frames btw! :)
Thanks,
Vinay