Add thoas ingress manifest

ensembl_thoas_ingress.yaml

+apiVersion: extensions/v1beta1
+kind: Ingress
+metadata:
+  name: ensembl-thoas-<SUB_DOMAIN>-ingress
+  annotations:
+    nginx.ingress.kubernetes.io/rewrite-target: /$2             
+spec:
+  rules:
+  - host: <SUB_DOMAIN>.review.ensembl.org
+    http:
+      paths:  
+        - path: /thoas($|/)(.*)
+          backend:
+            serviceName: thoas-server-<DEPLOYMENT_ENV>-svc
+            servicePort: 8000
\ No newline at end of file