some cleanup for invitation changes

atst/domain/workspaces/query.py

@@ -32,12 +32,3 @@ class WorkspacesQuery(Query):
     @classmethod
     def create_workspace_role(cls, user, role, workspace, **kwargs):
         return WorkspaceRole(user=user, role=role, workspace=workspace, **kwargs)
-
-    @classmethod
-    def get_role_for_workspace_and_user(cls, workspace, user):
-        return (
-            db.session.query(WorkspaceRole)
-            .filter(WorkspaceRole.user == user)
-            .filter(WorkspaceRole.workspace == workspace)
-            .one()
-        )

atst/models/invitation.py

@@ -41,8 +41,8 @@ class Invitation(Base, TimestampsMixin, AuditableMixin):
     token = Column(String(), index=True, default=lambda: secrets.token_urlsafe())
 
     def __repr__(self):
-        return "<Invitation(user='{}', workspace='{}', id='{}')>".format(
-            self.user.id, self.workspace.id, self.id
+        return "<Invitation(user='{}', workspace_role='{}', id='{}')>".format(
+            self.user_id, self.workspace_role_id, self.id
         )
 
     @property

atst/routes/errors.py

@@ -44,7 +44,7 @@ def make_error_pages(app):
 
     @app.errorhandler(InvitationError)
     # pylint: disable=unused-variable
-    def expired_invitation(e):
+    def invalid_invitation(e):
         log_error(e)
         return (
             render_template(