fake-sendmail: put the executable in $out/bin/sendmail
fake-sendmail: put the executable in $out/bin/sendmail

This is necessary as fake-sendmail is meant to be a drop-in
replacement for `sendmail`. Programs expect it as that
in the `$PATH`.

zalora/deployix,shlevy/defnix,zalora/defnix,zalora/deployix,zalora/defnix,shlevy/defnix