Increase run_script timeout to fix failing test
Increase run_script timeout to fix failing test

There was a call to `run_script` in
`integration.shell.test_saltcli.RetcodeTestCase.test_missing_minion`
which I had set to timeout after 20 seconds. The problem with this is
that on my laptop, which has a Core i7 and plentiful quantities of RAM
with which to run the test, it still takes about 17 seconds to complete.
So, on any slightly-less-powerful machine, the test is likely to (at
least occasionally) that artificial 20-second limit and time out, which
will cause the test to fail.

This increases that timeout to 60 seconds to ensure that the test has
enough time to complete.

saltstack/salt,saltstack/salt,saltstack/salt,saltstack/salt,saltstack/salt