feat(Dropdown): Convert dropdown to typescript

packages/patternfly-4/.babelrc

@@ -1,6 +1,6 @@
 {
   "presets": ["@babel/react"],
-  "ignore": ["**/__snapshots__", "**/*.d.ts"],
+  "ignore": ["**/__snapshots__", "**/*.d.ts", "**/*.test.*"],
   "plugins": [
     "@babel/plugin-transform-typescript",
     "babel-plugin-typescript-to-proptypes",

packages/patternfly-4/react-core/src/components/ApplicationLauncher/ApplicationLauncher.test.js

@@ -2,10 +2,10 @@ import React from 'react';
 import { mount } from 'enzyme';
 import { HelpIcon } from '@patternfly/react-icons';
 import { ApplicationLauncher } from './ApplicationLauncher';
-import DropdownItem from '../Dropdown/DropdownItem';
+import { DropdownItem } from '../Dropdown/DropdownItem';
 
 import { DropdownPosition, DropdownDirection } from '../Dropdown/dropdownConstants';
-import DropdownSeparator from '../Dropdown/Separator';
+import { DropdownSeparator } from '../Dropdown/Separator';
 
 const dropdownItems = [
   <DropdownItem key="link">Link</DropdownItem>,

packages/patternfly-4/react-core/src/components/ApplicationLauncher/ApplicationLauncher.tsx

@@ -63,6 +63,7 @@ export class ApplicationLauncher extends React.Component<ApplicationLauncherProp
       isGrouped,
       dropdownItems,
       items,
+      ref,
       ...props
     } = this.props;
     return (