delete objects based on label

This PR uses the "SelectorFromSet()" function which takes alabel or
selector as an argument returns all the object that uses that label or
selector. Once we get the object that uses a particular label we can
further do the delete operation on them. This is similar to "kubectl
delete <object> --selector=<key>=<value>". Also the label has been
modified from service to io.kompose.service.

script/test/fixtures/entrypoint-command/output-k8s.json

@@ -3,6 +3,33 @@
   "apiVersion": "v1",
   "metadata": {},
   "items": [
+    {
+      "kind": "Service",
+      "apiVersion": "v1",
+      "metadata": {
+        "name": "base",
+        "creationTimestamp": null,
+        "labels": {
+          "io.kompose.service": "base"
+        }
+      },
+      "spec": {
+        "ports": [
+          {
+            "name": "headless",
+            "port": 55555,
+            "targetPort": 0
+          }
+        ],
+        "selector": {
+          "io.kompose.service": "base"
+        },
+        "clusterIP": "None"
+      },
+      "status": {
+        "loadBalancer": {}
+      }
+    },
     {
       "kind": "Deployment",
       "apiVersion": "extensions/v1beta1",
@@ -16,7 +43,7 @@
           "metadata": {
             "creationTimestamp": null,
             "labels": {
-              "service": "base"
+              "io.kompose.service": "base"
             }
           },
           "spec": {
@@ -39,33 +66,6 @@
         "strategy": {}
       },
       "status": {}
-    },
-    {
-      "kind": "Service",
-      "apiVersion": "v1",
-      "metadata": {
-        "name": "base",
-        "creationTimestamp": null,
-        "labels": {
-          "service": "base"
-        }
-      },
-      "spec": {
-        "ports": [
-          {
-            "name": "headless",
-            "port": 55555,
-            "targetPort": 0
-          }
-        ],
-        "selector": {
-          "service": "base"
-        },
-        "clusterIP": "None"
-      },
-      "status": {
-        "loadBalancer": {}
-      }
     }
   ]
 }

script/test/fixtures/entrypoint-command/output-os.json

@@ -10,7 +10,7 @@
         "name": "base",
         "creationTimestamp": null,
         "labels": {
-          "service": "base"
+          "io.kompose.service": "base"
         }
       },
       "spec": {
@@ -22,7 +22,7 @@
           }
         ],
         "selector": {
-          "service": "base"
+          "io.kompose.service": "base"
         },
         "clusterIP": "None"
       },
@@ -37,7 +37,7 @@
         "name": "base",
         "creationTimestamp": null,
         "labels": {
-          "service": "base"
+          "io.kompose.service": "base"
         }
       },
       "spec": {
@@ -65,13 +65,13 @@
         "replicas": 1,
         "test": false,
         "selector": {
-          "service": "base"
+          "io.kompose.service": "base"
         },
         "template": {
           "metadata": {
             "creationTimestamp": null,
             "labels": {
-              "service": "base"
+              "io.kompose.service": "base"
             }
           },
           "spec": {
@@ -99,7 +99,10 @@
       "apiVersion": "v1",
       "metadata": {
         "name": "base",
-        "creationTimestamp": null
+        "creationTimestamp": null,
+        "labels": {
+          "io.kompose.service": "base"
+        }
       },
       "spec": {
         "tags": [