Upgrade snappy-java to 1.1.2.6

We should upgrade the snappy-java version to pick up the following fix we see at https://github.com/xerial/snappy-java/blob/master/Milestone.md

More info on the fix with one user commenting it impacts kafka 0.10 (http://www.confluent.io/blog/announcing-apache-kafka-0.10-and-confluent-platform-3.0): https://github.com/xerial/snappy-java/issues/142

Fix will involve the pom and the dev/deps files which mention versions of each library we use.

I'll create a PR and not expecting new failures to pop up...