Changing how constraints are handled internally (#115)

* Updating Changelog to reflect what's changing in 1.22.1

* Bug fix: Setting the same constraint multiple times is no longer allowed.

* Constraints map has been added to handle constraints being added to Aurora Jobs.

* Lowering timeout to avoid flaky test for bad payload timeout.

* Adding attributes to Mesos agents in order to test limits by constraint.



* Make two instances schedulable per zone in order to experience flaky behavior.

docker-compose.yml

@@ -38,6 +38,7 @@ services:
     ports:
     - "5051:5051"
     environment:
+      MESOS_ATTRIBUTES: 'zone:west'
       MESOS_MASTER: zk://192.168.33.2:2181/mesos
       MESOS_CONTAINERIZERS: docker,mesos
       MESOS_PORT: 5051
@@ -62,6 +63,7 @@ services:
     ports:
       - "5061:5061"
     environment:
+      MESOS_ATTRIBUTES: 'zone:east'
       MESOS_MASTER: zk://192.168.33.2:2181/mesos
       MESOS_CONTAINERIZERS: docker,mesos
       MESOS_HOSTNAME: localhost