Generate invite tokens from admin-fe

This MR allows to create invite tokens, list them on a separate tab, invite users via email. It also updates error handling and allows to generate tokens for resetting password.

Closes #28 (closed)

src/router/index.js

@@ -129,7 +129,7 @@ export const asyncRouterMap = [
   ...(settingsDisabled ? [] : [settings]),
   ...(reportsDisabled ? [] : [reports]),
   ...(invitesDisabled ? [] : [invites]),
-  ...(emojiPacksDisabled ? [] : [emojiPacks])
+  ...(emojiPacksDisabled ? [] : [emojiPacks]),
   {
     path: '/users/:id',
     component: Layout,