Add Kafka paper and The Log post, closes #37

@@ -16,6 +16,7 @@
 * [MapReduce: Simplified Data Processing on Large Clusters](http://research.google.com/archive/mapreduce-osdi04.pdf) (Dean and Ghemawat)
 * [The Google File System](http://research.google.com/archive/gfs-sosp2003.pdf) (Ghemawat et al.)
 * [On Designing and Deploying Internet Scale Services](http://mvdirona.com/jrh/talksAndPapers/JamesRH_Lisa.pdf) (Hamilton)
+* [Kafka: A Distributed Messaging System for Log Processing](http://research.microsoft.com/en-us/UM/people/srikanth/netdb11/netdb11papers/netdb11-final12.pdf) (Kreps et al.)
 * [Dremel: Interactive Analysis of Web-Scale Datasets](http://static.googleusercontent.com/external_content/untrusted_dlcp/research.google.com/en/us/pubs/archive/36632.pdf) (Melnik et al.)
 * [Out of the Tar Pit](http://shaffner.us/cs/papers/tarpit.pdf) (Moseley and Marks)
 * [In Search of an Understandable Consensus Algorithm](https://ramcloud.stanford.edu/wiki/download/attachments/11370504/raft.pdf) (Ongaro and Ousterhout)
@@ -44,6 +45,7 @@
 * [The Trouble with Clocks](http://aphyr.com/posts/299-the-trouble-with-timestamps) (Kingsbury)
 * [Call Me Maybe: Final Thoughts](http://aphyr.com/posts/286-call-me-maybe-final-thoughts) (Kingsbury)
 * [Getting Real About Distributed Systems Reliability](http://blog.empathybox.com/post/19574936361/getting-real-about-distributed-system-reliability) (Kreps)
+* [The Log: What every software engineer should know about real-time data's unifying abstraction](http://engineering.linkedin.com/distributed-systems/log-what-every-software-engineer-should-know-about-real-time-datas-unifying) (Kreps)
 * [Incident Response at Heroku](https://blog.heroku.com/archives/2014/5/9/incident-response-at-heroku) (McGranaghan)
 * [On HTTP Load Testing](http://www.mnot.net/blog/2011/05/18/http_benchmark_rules) (Nottingham)
 * [Observability at Twitter](https://blog.twitter.com/2013/observability-at-twitter) (Watson)