Update dev-dependencies

Author: wooorm

package.json

@@ -37,14 +37,14 @@
   "dependencies": {},
   "devDependencies": {
     "mdast-util-from-markdown": "^0.8.0",
-    "mdast-util-to-markdown": "^0.5.0",
+    "mdast-util-to-markdown": "^0.6.0",
     "micromark-extension-gfm-autolink-literal": "^0.5.0",
     "nyc": "^15.0.0",
     "prettier": "^2.0.0",
     "remark-cli": "^9.0.0",
     "remark-preset-wooorm": "^8.0.0",
     "tape": "^5.0.0",
-    "xo": "^0.35.0"
+    "xo": "^0.37.0"
   },
   "scripts": {
     "format": "remark . -qfo && prettier . -w --loglevel warn && xo --fix",