Removed accidentally checked in comment

It looks like this comment was added a while ago by @mridulm as part of a merge and was accidentally checked in.  We should remove it.

Author: Kay Ousterhout <kayousterhout@gmail.com>

Closes #61 from kayousterhout/remove_comment and squashes the following commits:

0b2b3f2 [Kay Ousterhout] Removed accidentally checked in comment
update proportion of memory

The default value of "spark.storage.memoryFraction" has been changed from 0.66 to 0.6 . So it should be 60% of the memory to cache while 40% used for task execution.

Author: Chen Chao <crazyjvm@gmail.com>

Closes #66 from CrazyJvm/master and squashes the following commits:

0f84d86 [Chen Chao] update proportion of memory
Remove the remoteFetchTime metric.

This metric is confusing: it adds up all of the time to fetch
shuffle inputs, but fetches often happen in parallel, so
remoteFetchTime can be much longer than the task execution time.

@squito it looks like you added this metric -- do you have a use case for it?

cc @shivaram -- I know you've looked at the shuffle performance a lot so chime in here if this metric has turned out to be useful for you!

Author: Kay Ousterhout <kayousterhout@gmail.com>

Closes #62 from kayousterhout/remove_fetch_variable and squashes the following commits:

43341eb [Kay Ousterhout] Remote the remoteFetchTime metric.
Added a unit test for PairRDDFunctions.lookup

Lookup didn't have a unit test. Added two tests, one for with a partitioner, and one for without.

Author: Bryn Keller <bryn.keller@intel.com>

Closes #36 from xoltar/lookup and squashes the following commits:

3bc0d44 [Bryn Keller] Added a unit test for PairRDDFunctions.lookup