Remove object-assign dependency

Closes GH-4.

Reviewed-by: Titus Wormer <[email protected]>

Author: ChristianMurphy

index.js

@@ -1,7 +1,5 @@
 'use strict'
 
-var assign = require('object-assign')
-
 module.exports = u
 
 function u(type, props, value) {
@@ -15,7 +13,7 @@ function u(type, props, value) {
     props = {}
   }
 
-  node = assign({type: String(type)}, props)
+  node = Object.assign({type: String(type)}, props)
 
   if (Array.isArray(value)) {
     node.children = value

package.json

@@ -28,9 +28,7 @@
     "types/index.d.ts"
   ],
   "types": "types/index.d.ts",
-  "dependencies": {
-    "object-assign": "^4.1.0"
-  },
+  "dependencies": {},
   "devDependencies": {
     "@types/mdast": "^3.0.0",
     "dtslint": "^0.9.9",