remove go:1.11 kind; update go:1.15 to use 1.17.0 release (#674)

Author: dgrove-oss

helm/openwhisk/runtimes.json

@@ -174,20 +174,6 @@
             }
         ],
         "go": [
-            {
-                "kind": "go:1.11",
-                "default": false,
-                "deprecated": true,
-                "attached": {
-                    "attachmentName": "codefile",
-                    "attachmentType": "text/plain"
-                },
-                "image": {
-                    "prefix": "openwhisk",
-                    "name": "action-golang-v1.11",
-                    "tag": "1.15.0"
-                }
-            },
             {
                 "kind": "go:1.15",
                 "default": true,
@@ -199,7 +185,7 @@
                 "image": {
                     "prefix": "openwhisk",
                     "name": "action-golang-v1.15",
-                    "tag": "1.16.0"
+                    "tag": "1.17.0"
                 }
             }
         ],