Error in the README.md for kmer.scala example, need to get rdd first.

[InvisibleTech]

When I ran the example from the README for kmer.scala I received errors trying to flatMap:

error: value flatMap is not a member of org.bdgenomics.adam.rdd.read.AlignmentRecordRDD

By using .rdd:

reads.rdd.flatMap(_.getSequence.sliding(21).map(k => (k, 1L)))....
It works.

[AmplabJenkins]

Can one of the admins verify this patch?

[fnothaft]

Jenkins, test this please.

[fnothaft]

Thanks for the patch, @InvisibleTech! We've just made that API change recently and forgot to patch the docs, so thank you for updating the docs after you ran into the issue!

[AmplabJenkins]

Test PASSed.
Refer to this link for build results (access rights to CI server needed):
https://amplab.cs.berkeley.edu/jenkins//job/ADAM-prb/1230/
Test PASSed.

[heuermh]

@fnothaft shouldn't the implicit take care of this?

[fnothaft]

@heuermh good point, I was just thinking that. I think the correct approach would be to add the implicit conversion. We just import import org.bdgenomics.adam.rdd.ADAMContext, not import org.bdgenomics.adam.rdd.ADAMContext._

[InvisibleTech]

Got it... I ran the example with the wildcard implicit and it works. Though... not sure if this a Spark 1.6 or OSX Spark thing but if you don't end the code lines for the val kmers = .... line you end up with spark shell errors running the kmer.scala sample. I'll post a new PR for this. thanks for the review... who'd have thought a README review could be so useful.

[InvisibleTech]

Please see #1033 for my better fix per your suggestion.

[heuermh]

Closing in favor of #1033, thanks!