[bug] warning output from docker exec shown when should be hidden

[GeoffWilliams]

non-zero exit status: 2 from ["bash", "-c", "export TERM=xterm LC_ALL=C PATH=/usr/local/bats/bin:/opt/puppetlabs/puppet/bin:$PATH; cd /testcase ; puppet apply --detailed-exitcodes examples/init.pp"]: ["\e[mNotice: Compiled catalog for 765d3370b6c0 in environment production in 0.08 seconds\e[0m\r\n", "\e[mNotice: /Stage[main]/Main/Chown_r[/tmp/foo]/Exec[chown -R for /tmp/foo]/returns: executed successfully\e[0m\r\n", "\e[mNotice: Applied catalog in 0.03 seconds\e[0m\r\n"] []

• We're not supposed to show puppet in this kind of output due to non-zero status not being a problem