Include antlr3 and stringtemplate from JPackage on el6

Those two packages are not present in CentOS 6, but
are required by Drools. Drools is then used in
ovirt-optimizer, which is a new component from the
SLA kitchen.

Change-Id: I2bde18752ae739de468257f3a51ec8b3326ce5f4
Signed-off-by: Martin Sivak <msivak@redhat.com>