Prevent corrupted styled-jsx styles in production.

See: https://github.com/zeit/styled-jsx/issues/602

app/.babelrc

@@ -1,4 +1,13 @@
 {
-  "presets": ["next/babel"],
+  "presets": [
+    [
+      "next/babel",
+      {
+        "styled-jsx": {
+          "optimizeForSpeed": false
+        }
+      }
+    ]
+  ],
   "plugins": ["transform-inline-environment-variables", "graphql-tag"]
 }