interface: create 'default apps' library

We don't want to maintain several indexes of the Landscape suite when we
want to special case something. Now we don't.

pkg/interface/src/apps/launch/components/tiles/basic.js

@@ -1,6 +1,7 @@
 import React  from 'react';
 import classnames from 'classnames';
 import { Link } from 'react-router-dom';
+import defaultApps from '../../../../lib/default-apps';
 
 import Tile from './tile';
 
@@ -29,7 +30,9 @@ export default class BasicTile extends React.PureComponent {
       </span>
     );
 
-    const routeList = ['/~chat', '/~publish', '/~link', '/~groups', '/~dojo'];
+    const routeList = defaultApps.map((e) => {
+      return `/~${e}`;
+    });
 
     const tile =  ( routeList.indexOf(props.linkedUrl) !== -1 ) ? (
       <Link className="w-100 h-100 db pa2 no-underline" to={props.linkedUrl}>

pkg/interface/src/lib/default-apps.js

@@ -0,0 +1,3 @@
+const defaultApps = ['chat', 'dojo', 'groups', 'link', 'publish'];
+
+export default defaultApps;