Show visual feedback on login error, redirect on success

src/components/login_form/login_form.js

@@ -1,13 +1,17 @@
 const LoginForm = {
   data: () => ({
-    user: {}
+    user: {},
+    authError: false
   }),
   computed: {
     loggingIn () { return this.$store.state.users.loggingIn }
   },
   methods: {
     submit () {
-      this.$store.dispatch('loginUser', this.user)
+      this.$store.dispatch('loginUser', this.user).then(
+        () => { this.$router.push('/main/friends')}, 
+        () => { this.authError = true }
+      )
     }
   }
 }