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/AuthAdapter.js

@@ -0,0 +1,22 @@
+/*eslint no-unused-vars: "off"*/
+export class AuthAdapter {
+
+  /*
+  @param appIds: the specified app ids in the configuration
+  @param authData: the client provided authData
+  @returns a promise that resolves if the applicationId is valid
+   */
+  validateAppId(appIds, authData) {
+    return Promise.resolve({});
+  }
+
+  /*
+  @param authData: the client provided authData
+  @param options: additional options
+   */
+  validateAuthData(authData, options) {
+    return Promise.resolve({});
+  }
+}
+
+export default AuthAdapter;