send output of `cat /etc/os-release` to /dev/null

[dethmasque]

Connect uses r-install to provision vagrant boxes and we are seeing a lot of:

   centos6-plain: cat: /etc/os-release: No such file or directory
    centos6-plain: cat: /etc/os-release: No such file or directory
    centos6-plain: cat: /etc/os-release: No such file or directory
    centos6-plain: cat: /etc/os-release: No such file or directory
    centos6-plain: cat: /etc/os-release: No such file or directory
    centos6-plain: cat: /etc/os-release: No such file or directory
    centos6-plain: cat: /etc/os-release: No such file or directory