[WIP] New user can now accept invite and will be made to

register. On succesful register and verfication they
will be added to service and forwarded to dashboard.

Nothing is done yet with the permissions requested in the
invite to the user.

app/main/views/invites.py

@@ -1,7 +1,8 @@
 from flask import (
     redirect,
     url_for,
-    abort
+    abort,
+    session
 )
 
 from notifications_python_client.errors import HTTPError
@@ -15,6 +16,7 @@ from app import (
 
 @main.route("/invitation/<token>")
 def accept_invite(token):
+
     try:
         invited_user = invite_api_client.accept_invite(token)
         existing_user = user_api_client.get_user_by_email(invited_user.email_address)
@@ -22,11 +24,11 @@ def accept_invite(token):
         if existing_user:
             user_api_client.add_user_to_service(invited_user.service,
                                                 existing_user.id)
-
             return redirect(url_for('main.service_dashboard', service_id=invited_user.service))
         else:
-            # TODO implement registration flow for new users
-            abort(404)
+            session['invited_user'] = invited_user.serialize()
+            return redirect(url_for('main.register_from_invite'))
+
     except HTTPError as e:
         if e.status_code == 404:
             abort(404)