async function getAccessToken(req, res) {
    const scope = req.body.scope || ['dashboard:write', 'dashboard:read'];
    const session = await gladys.session.getAccessToken(req.body.refresh_token, scope);
    res.json(session);
  }
@api {post} /api/v1/access_token getAccessToken
@apiName getAccessToken
@apiGroup User