$ bash --version
GNU bash, version 4.2.25(1)-release (x86_64-pc-linux-gnu)
$ bats tests/unit/20_docker-options.bats
...
11 tests, 6 failures
$ sudo apt-get install -y -q bash=$(apt-cache show bash | egrep "^Version: 4.3" | head -1 | awk -F: '{ print $2 }' | xargs)
...
Setting up bash (4.3-7ubuntu1.5) ...
...
$ bash --version
GNU bash, version 4.3.11(1)-release (x86_64-pc-linux-gnu)
$ bats tests/unit/20_docker-options.bats
...
11 tests, 0 failures