Add make target to build the tool
Add make target to build the tool

Currently it isn't possible to build the tool without also executing it.
This patch adds a new 'tool' target to the Makefile that only builds it.

Change-Id: If10c086f4096071e547ffd313e2192326ae5068a
Signed-off-by: Juan Hernandez <59e5b8140de97cc91c3fb6c5342dce948469af8c@redhat.com>

jhernand/ovirt-containers,jhernand/ovirt-containers