Bash assertions

[orangemug]

We currently have experimental support for bash (see https://github.com/orangemug/readme-tester/tree/master/test/examples/bash)

We include https://github.com/orangemug/bash-assert which allows for variable testing

out=`some-command`
assert $out == "some output"

Unix exit codes tests

some-command
assert $? == 0

stdout/stderr tests

echo "foo" > /tmp/foo-stdout.txt
## >>/tmp/foo-stdout.txt
## foo
## <<

Are there any opinions of the current API?