Adds support for Tier and SlaPolicy to the Job interface (#99)

* Adding parameter for Aurora so that we're able to run SLA aware updates with less than 20 instances. Lowered time it takes to run test by reducing watch time per instance as well.

* Reducing the number of instances and time for SLA aware instances in docker-compose set up.

* Adding another Mesos agent to the docker-compose setup.

* Huge thanks to @zircote for this contribution.

docker-compose.yml

@@ -55,6 +55,30 @@ services:
     depends_on:
     - zk
 
+  agent-two:
+    image: rdelvalle/mesos-agent:1.5.1
+    pid: host
+    restart: on-failure
+    ports:
+      - "5061:5061"
+    environment:
+      MESOS_MASTER: zk://192.168.33.2:2181/mesos
+      MESOS_CONTAINERIZERS: docker,mesos
+      MESOS_HOSTNAME: localhost
+      MESOS_PORT: 5061
+      MESOS_RESOURCES: ports(*):[11000-11999]
+      MESOS_SYSTEMD_ENABLE_SUPPORT: 'false'
+      MESOS_WORK_DIR: /tmp/mesos
+    networks:
+      aurora_cluster:
+        ipv4_address: 192.168.33.5
+
+    volumes:
+      - /sys/fs/cgroup:/sys/fs/cgroup
+      - /var/run/docker.sock:/var/run/docker.sock
+    depends_on:
+      - zk
+
   aurora-one:
     image: rdelvalle/aurora:0.21.0
     pid: host
@@ -65,6 +89,7 @@ services:
       CLUSTER_NAME: test-cluster
       ZK_ENDPOINTS: "192.168.33.2:2181"
       MESOS_MASTER: "zk://192.168.33.2:2181/mesos"
+      EXTRA_SCHEDULER_ARGS: "-min_required_instances_for_sla_check=1"
     networks:
       aurora_cluster:
         ipv4_address: 192.168.33.7