finish rudimentary auth flow

Server/api/auth.js

@@ -51,6 +51,10 @@ module.exports = (R, $) => {
   })
 
   R.get('/api/auth/redirect', ctx => {
-    ctx.redirect($.discord.getAuthUrl())
+    ctx.body = { url: $.discord.getAuthUrl() }
+  })
+
+  R.post('/api/auth/logout', ctx => {
+    ctx.session = null
   })
 }

Server/services/discord.js

@@ -92,6 +92,10 @@ class DiscordService extends Service {
   async getUser (authToken) {
     const url = 'https://discordapp.com/api/v6/users/@me'
     try {
+      if (authToken == null || authToken === '') {
+        throw new Error('not logged in')
+      }
+
       const rsp =
         await superagent
           .get(url)