Remove 1.6.x upgrade tests.

examples/k8s-upgrade/v1.7.7.json

@@ -6,7 +6,7 @@
       "orchestratorVersion": "1.7.7"
     },
     "masterProfile": {
-      "count": 1,
+      "count": 3,
       "dnsPrefix": "",
       "vmSize": "Standard_D2_v2",
       "storageProfile" : "ManagedDisks"

examples/k8s-upgrade/v1.8.4.json

@@ -6,7 +6,7 @@
       "orchestratorVersion": "1.8.4"
     },
     "masterProfile": {
-      "count": 1,
+      "count": 3,
       "dnsPrefix": "",
       "vmSize": "Standard_D2_v2",
       "storageProfile" : "ManagedDisks"

test/acse-conf/acse-upgrade-lnx.json

@@ -1,13 +1,5 @@
 {
   "deployments": [
-    {
-      "cluster_definition": "k8s-upgrade/v1.6.11.json",
-      "location": "centralus"
-    },
-    {
-      "cluster_definition": "k8s-upgrade/v1.6.13.json",
-      "location": "westus2"
-    },
     {
       "cluster_definition": "k8s-upgrade/v1.7.7.json",
       "location": "eastus"