update sapper to set etag for HTML pages as well

package-lock.json

@@ -8875,7 +8875,7 @@
       }
     },
     "sapper": {
-      "version": "github:nolanlawson/sapper#45da9baab5e1fa86d7861f51953fee6bb6552115",
+      "version": "github:nolanlawson/sapper#9cd44cc6f65e6e6c2dd92ed0ddf1149a649ecf29",
       "requires": {
         "chalk": "2.4.0",
         "chokidar": "1.7.0",

package.json

@@ -64,7 +64,7 @@
     "pify": "3.0.0",
     "quick-lru": "1.1.0",
     "requestidlecallback": "0.3.0",
-    "sapper": "github:nolanlawson/sapper#for-pinafore-4",
+    "sapper": "github:nolanlawson/sapper#for-pinafore-5",
     "serve-static": "1.13.2",
     "shrink-ray-current": "2.1.0",
     "stringz": "1.0.0",