Fix the python version comparison.

The comparison to (2, 6) doesn't seem to be correct.

For example:

>>> import sys
>>> sys.version_info <= (2, 6)
False
>>> sys.version_info[0:2] <= (2, 6)
True
>>> sys.version_info
(2, 6, 6, 'final', 0)

Change-Id: I2076d23e58a8777fe4bab81665b9b570656561e9
Merge "Fix the python version comparison."