Remove Get and Set tests from GetSetPerformanceTests

Motivation
----------
They didn't measure performance and are duplicated elsewhere.

Modifications
-------------
Removed the Get and Set tests from GetSetPerformanceTests.

Result
------
Those two tests will no longer be run.

Change-Id: I7b4098ce21c4071bf02d056af2b5c6831e64edd8
Reviewed-on: http://review.couchbase.org/44447
Reviewed-by: Simon Baslé <simon@couchbase.com>
Tested-by: Jeffry Morris <jeffrymorris@gmail.com>