unrecognized arguments: --early-adopter

Hi!

It seems that the published version of this package does not support the flag.

See:
```
$ pip3 install --user starttls-policy-cli
Collecting starttls-policy-cli
Downloading https://files.pythonhosted.org/packages/96/30/950945d02f6db4454cb96d5aaf0aee9f72959ea912a8625f9e7b6571225a/starttls_policy_cli-0.0.0.dev20190103-py2.py3-none-any.whl
$ pip3 show starttls-policy-cli
Name: starttls-policy-cli
Version: 0.0.0.dev20190103
Summary: Policy API for STARTTLS Preload
Home-page: https://github.com/EFForg/starttls-everywhere
Author: Sydney Li
Author-email: sydney@eff.org
License: Apache License 2.0
Location: /home/lorenz/.local/lib/python3.7/site-packages
Requires: python-dateutil, setuptools, datetime, six
Required-by:
$ starttls-policy-cli --generate postfix --early-adopter --policy-dir /home/lorenz/tmp
usage: starttls-policy-cli [-h] --generate GENERATE [--policy-dir POLICY_DIR]
starttls-policy-cli: error: unrecognized arguments: --early-adopter
```

Please publish a new version!