Auth Adapters refactoring (#3177)

* Moves all authentication providers to Adapter/Auth

* refactors specs

* Deprecates oauth option in favor of auth option

- Deprecates facebookAppIds option (in favor of auth.facebook.appIds)
- Adds warnings about the deprecated options

* nits

src/Adapters/Auth/wechat.js

@@ -0,0 +1,41 @@
+// Helper functions for accessing the WeChat Graph API.
+var https = require('https');
+var Parse = require('parse/node').Parse;
+
+// Returns a promise that fulfills iff this user id is valid.
+function validateAuthData(authData) {
+  return graphRequest('auth?access_token=' + authData.access_token +'&openid=' +authData.id).then(function (data) {
+    if (data.errcode == 0) {
+      return;
+    }
+    throw new Parse.Error(Parse.Error.OBJECT_NOT_FOUND, 'qq auth is invalid for this user.');
+  });
+}
+
+// Returns a promise that fulfills if this app id is valid.
+function validateAppId() {
+  return Promise.resolve();
+}
+
+// A promisey wrapper for WeChat graph requests.
+function graphRequest(path) {
+  return new Promise(function (resolve, reject) {
+    https.get('https://api.weixin.qq.com/sns/' + path, function (res) {
+      var data = '';
+      res.on('data', function (chunk) {
+        data += chunk;
+      });
+      res.on('end', function () {
+        data = JSON.parse(data);
+        resolve(data);
+      });
+    }).on('error', function () {
+      reject('Failed to validate this access token with weixin.');
+    });
+  });
+}
+
+module.exports = {
+  validateAppId,
+  validateAuthData
+};