Adds Proptypes to AddDropDownButton Component

Also refactors to use the url that is passed in as the key for the link.
This means that we don't have to pass in a key value.

awx/ui_next/src/components/AddDropDownButton/AddDropDownButton.jsx

@@ -1,5 +1,6 @@
 import React, { useState, useRef, useEffect } from 'react';
 import { Link } from 'react-router-dom';
+import PropTypes from 'prop-types';
 import { Dropdown, DropdownPosition } from '@patternfly/react-core';
 import { ToolbarAddButton } from '@components/PaginatedDataList';
 
@@ -30,7 +31,7 @@ function AddDropDownButton({ dropdownItems }) {
         dropdownItems={dropdownItems.map(item => (
           <Link
             className="pf-c-dropdown__menu-item"
-            key={item.key}
+            key={item.url}
             to={item.url}
           >
             {item.label}
@@ -41,5 +42,14 @@ function AddDropDownButton({ dropdownItems }) {
   );
 }
 
+AddDropDownButton.propTypes = {
+  dropdownItems: PropTypes.arrayOf(
+    PropTypes.shape({
+      label: PropTypes.string.isRequired,
+      url: PropTypes.string.isRequired,
+    })
+  ).isRequired,
+};
+
 export { AddDropDownButton as _AddDropDownButton };
 export default AddDropDownButton;

awx/ui_next/src/screens/Inventory/InventoryList/InventoryList.jsx

@@ -152,12 +152,10 @@ class InventoriesList extends Component {
         key="add"
         dropdownItems={[
           {
-            key: 'inventory',
             label: i18n._(t`Inventory`),
             url: `${match.url}/inventory/add/`,
           },
           {
-            key: 'smart-inventory',
             label: i18n._(t`Smart Inventory`),
             url: `${match.url}/smart_inventory/add/`,
           },

awx/ui_next/src/screens/Template/TemplateList/TemplateList.jsx

@@ -166,12 +166,10 @@ class TemplatesList extends Component {
         key="add"
         dropdownItems={[
           {
-            key: 'template',
             label: i18n._(t`Template`),
             url: `${match.url}/template/add/`,
           },
           {
-            key: 'workflow_template',
             label: i18n._(t`Workflow Template`),
             url: `${match.url}/_workflow/add/`,
           },