Docker image for cwltool does not work on Docker v17.06.2-ce-mac27

The following command does not work on Mac OSX with Docker Community Edition v17.06.2-ce-mac27:

```console
$ docker run --privileged -ti --rm commonworkflowlanguage/cwltool
```
## Expected Behavior
It shows the help message for cwltool.

## Actual Behavior
It shows an error message and the help message for docker before showing the help message for cwltool.
I guess it is not an intended behavior.

```console
$ docker run --privileged -ti --rm commonworkflowlanguage/cwltool master
/dev/mapper/control: open failed: No such device
Failure to communicate with kernel device-mapper driver.
Check that device-mapper is available in the kernel.
Command failed
ln: failed to create symbolic link '/sys/fs/cgroup/systemd/name=systemd': Operation not permitted
ln: failed to create symbolic link '/sys/fs/cgroup/openrc/name=openrc': Operation not permitted
unknown shorthand flag: 'd' in -d
See 'docker --help'.

Usage: docker COMMAND

A self-sufficient runtime for containers

Options:
--config string Location of client config files (default

...

wait Block until one or more containers stop, then print their exit codes

Run 'docker COMMAND --help' for more information on a command.

Timed out trying to connect to internal docker host.
/usr/local/bin/cwltool 1.0

CWL document required, no input file was provided
usage: cwltool [-h] [--basedir BASEDIR] [--outdir OUTDIR] [--no-container]
...
```