[SPARK-1105] fix site scala version error in doc

https://spark-project.atlassian.net/browse/SPARK-1105

fix site scala version error

Author: CodingCat <zhunansjtu@gmail.com>

Closes apache#616 from CodingCat/doc_version and squashes the following commits:

eafd99a [CodingCat] fix site scala version error in doc

Author: CodingCat

docs/_config.yml

@@ -5,7 +5,7 @@ markdown: kramdown
 # of Spark, Scala, and Mesos.
 SPARK_VERSION: 1.0.0-incubating-SNAPSHOT
 SPARK_VERSION_SHORT: 1.0.0
-SCALA_VERSION: "2.10"
+SCALA_VERSION: "2.10.3"
 MESOS_VERSION: 0.13.0
 SPARK_ISSUE_TRACKER_URL: https://spark-project.atlassian.net
 SPARK_GITHUB_URL: https://github.com/apache/incubator-spark