Revert "Replace hasOwnProperty with the more robust "has" package"

This reverts commit e6a9b28.

factoryWithTypeCheckers.js

@@ -8,7 +8,6 @@
 'use strict';
 
 var assign = require('object-assign');
-var has = require('has');
 
 var ReactPropTypesSecret = require('./lib/ReactPropTypesSecret');
 var checkPropTypes = require('./checkPropTypes');
@@ -319,7 +318,7 @@ module.exports = function(isValidElement, throwOnDirectAccess) {
         return new PropTypeError('Invalid ' + location + ' `' + propFullName + '` of type ' + ('`' + propType + '` supplied to `' + componentName + '`, expected an object.'));
       }
       for (var key in propValue) {
-        if (has(propValue, key)) {
+        if (Object.prototype.hasOwnProperty.call(propValue, key)) {
           var error = typeChecker(propValue, key, componentName, location, propFullName + '.' + key, ReactPropTypesSecret);
           if (error instanceof Error) {
             return error;

package.json

@@ -26,8 +26,7 @@
   "homepage": "https://facebook.github.io/react/",
   "dependencies": {
     "loose-envify": "^1.3.1",
-    "object-assign": "^4.1.1",
-    "has": "^1.0.1"
+    "object-assign": "^4.1.1"
   },
   "scripts": {
     "test": "jest",

yarn.lock

@@ -1239,7 +1239,7 @@ has-flag@^1.0.0:
   version "1.0.0"
   resolved "https://registry.yarnpkg.com/has-flag/-/has-flag-1.0.0.tgz#9d9e793165ce017a00f00418c43f942a7b1d11fa"
 
-has@^1.0.0, has@^1.0.1:
+has@^1.0.0:
   version "1.0.1"
   resolved "https://registry.yarnpkg.com/has/-/has-1.0.1.tgz#8461733f538b0837c9361e39a9ab9e9704dc2f28"
   dependencies: