update choo to v6

Author: joehand

package.json

@@ -69,7 +69,7 @@
     "bole": "^3.0.1",
     "brfs": "^1.4.3",
     "browserify": "^13.0.0",
-    "choo": "^5.0.0",
+    "choo": "^6.0.0",
     "choo-persist": "^3.0.2",
     "clipboard": "^1.6.1",
     "collect-stream": "^1.1.1",