In preparation for IGNITE-1701 to be committed soon, let's set the version of the spark for ignite-hadoop to be built with, so that the accelerator is created for the stack's component.
Bump Spark dependenency to 1.5.1 (the latest stable)
Until the Ignite's counterpart is committed, this patch won't have any effect at all, so it is safe to just commit it right away.
Pushed to the master. Will become effective one the Ignite JIRA is committed and next release is out.