Upgrade sass for Node 10 compatibility.

package.json

@@ -83,18 +83,18 @@
     "mkdirp": "0.5.1",
     "multi-glob": "1.0.1",
     "next-update": "^3.6.0",
-    "node-sass": "^4.7.2",
+    "node-sass": "^4.9.0",
     "npm-run-all": "^4.1.2",
     "onchange": "^3.3.0",
     "postcss": "^6.0.16",
     "postcss-safe-important": "^1.1.0",
-    "typescript": "^2.8.1",
     "pre-commit": "^1.2.2",
     "redux": "^3.7.2",
     "replace-x": "^1.5.0",
     "sass": "0.5.0",
     "temp-write": "^3.4.0",
     "tinyify": "^2.4.0",
+    "typescript": "^2.8.1",
     "uppy-server": "^0.11.2",
     "watchify": "^3.9.0",
     "wdio-mocha-framework": "^0.5.12",