Update dev-dependencies

Author: wooorm

package.json

@@ -45,7 +45,7 @@
   "devDependencies": {
     "browserify": "^16.0.0",
     "hyperscript": "^2.0.0",
-    "nyc": "^14.0.0",
+    "nyc": "^15.0.0",
     "prettier": "^1.0.0",
     "react": "^16.0.0",
     "react-dom": "^16.0.0",
@@ -59,7 +59,7 @@
     "virtual-dom": "^2.0.0",
     "vue": "^2.0.0",
     "vue-server-renderer": "^2.0.0",
-    "xo": "^0.25.0"
+    "xo": "^0.27.0"
   },
   "scripts": {
     "format": "remark . -qfo && prettier --write \"**/*.js\" && xo --fix",