Zookeeper free workload generator

Closes #146 (closed).

Still missing:

• Adapt Theodolite execution Kubernetes resources and Python scripts
• Adapt Docker configurations (to fix #106 (closed))

execution/uc-workload-generator/load-generator-service.yaml

+apiVersion: v1
+kind: Service
+metadata:
+  name: titan-ccp-load-generator
+  labels:
+    app: titan-ccp-load-generator
+spec:
+  type: ClusterIP
+  clusterIP: None
+  selector:
+    app: titan-ccp-load-generator
+  ports:
+  - name: coordination
+    port: 5701
+    targetPort: 5701
+    protocol: TCP