improve dev environment, enable HMR (#229)

package-lock.json

@@ -8875,7 +8875,7 @@
       }
     },
     "sapper": {
-      "version": "github:nolanlawson/sapper#87d01e4f5e6bd30ccfdbad54a74ae595030ad033",
+      "version": "github:nolanlawson/sapper#2124ca83c315457e7d6752507240e3ac440677bd",
       "requires": {
         "chalk": "2.4.1",
         "chokidar": "1.7.0",

package.json

@@ -71,7 +71,7 @@
     "pify": "3.0.0",
     "quick-lru": "1.1.0",
     "requestidlecallback": "0.3.0",
-    "sapper": "github:nolanlawson/sapper#for-pinafore-6",
+    "sapper": "github:nolanlawson/sapper#for-pinafore-7",
     "serve-static": "1.13.2",
     "shrink-ray-current": "2.1.0",
     "stringz": "1.0.0",

webpack.client.config.js

@@ -26,7 +26,8 @@ module.exports = {
             hydratable: true,
             emitCss: !isDev,
             cascade: false,
-            store: true
+            store: true,
+            hot: isDev
           }
         }
       },
@@ -49,8 +50,8 @@ module.exports = {
   node: {
     setImmediate: false
   },
-  optimization: {
-    minimizer: isDev ? [] : [
+  optimization: isDev ? {} : {
+    minimizer: [
       new UglifyWebpackPlugin({
         cache: true,
         parallel: true,