Update dev-dependencies

Author: wooorm

package.json

@@ -22,14 +22,14 @@
     "vfile-location": "^2.0.1"
   },
   "devDependencies": {
-    "browserify": "^14.1.0",
+    "browserify": "^16.0.0",
     "esmangle": "^1.0.1",
     "nyc": "^11.0.0",
-    "remark": "^8.0.0",
-    "remark-cli": "^4.0.0",
-    "remark-preset-wooorm": "^3.0.0",
+    "remark": "^9.0.0",
+    "remark-cli": "^5.0.0",
+    "remark-preset-wooorm": "^4.0.0",
     "tape": "^4.0.0",
-    "xo": "^0.18.0"
+    "xo": "^0.20.0"
   },
   "scripts": {
     "build-md": "remark . -qfo",
@@ -50,6 +50,11 @@
   "xo": {
     "space": true,
     "esnext": false,
+    "rules": {
+      "guard-for-in": "off",
+      "no-var": "off",
+      "prefer-arrow-callback": "off"
+    },
     "ignores": [
       "unist-util-source.js"
     ]

test.js

@@ -2,7 +2,7 @@
 
 var test = require('tape');
 var remark = require('remark');
-var source = require('./');
+var source = require('.');
 
 test('unist-util-source', function (t) {
   t.plan(10);