https://raw.githubusercontent.com/user/repo/master/cronjobs | crontab

echo "curl $(https://raw.githubusercontent.com/user/repo/master/cronjobs)" | crontab

% Total    % Received % Xferd  Average Speed   Time    Time     Time  Current
                                 Dload  Upload   Total   Spent    Left  Speed
  0     0    0     0    0     0      0      0 --:--:-- --:--:-- --:--:--     0...: command not found
100   505  100   505    0     0    804      0 --:--:-- --:--:-- --:--:--   804
(23) Failed writing body

curl https://raw.githubusercontent.com/user/repo/master/cronjobs | cat > crontab