MAINTENANCE: Automated closing of pull requests.

This commit exists to close the following pull requests on Github:

Closes #2915 (close requested by 'JoshRosen')
Closes #3140 (close requested by 'JoshRosen')
Closes #3366 (close requested by 'JoshRosen')
[SPARK-4632] version update

Author: Prabeesh K <prabsmails@gmail.com>

Closes #3495 from prabeesh/master and squashes the following commits:

ab03d50 [Prabeesh K] Update pom.xml
8c6437e [Prabeesh K] Revert
e10b40a [Prabeesh K] version update
dbac9eb [Prabeesh K] Revert
ec0b1c3 [Prabeesh K] [SPARK-4632] version update
a835505 [Prabeesh K] [SPARK-4632] version update
831391b [Prabeesh K]  [SPARK-4632] version update