- Add new requirements files to make it easier to install deps.
- Tox changes
- Update tox to use new requirements files.
- Tweak heading styles.
- Add development environment command `devenv`.
- Remove testenv command as it would run on devenv creation.
- Travis changes
- Now uses xenial as trusty is very old now.
- Trial run disabled to speed up tests.
- Add tox-venv for Python 3 support.
- Only install testssl if running security tests.
- Appveyor
- Add tox-venv for Python 3 support.
- Use requirements file for non-tox.
- Remove trial run to speed up testing.
The following error occured on Windows when switching to using HTTPS
url with Twisted Agent:
```
<class 'twisted.web._newclient.ResponseNeverReceived'>: [<twisted.python.failure.Failure OpenSSL.SSL.Error: [('SSL routines', 'tls_process_server_certificate', 'certificate verify failed')]>
```
The fix is to install certifi and provide the path to the trust store as
env var for OpenSSL to pick up.
Also includes a simplication of the core test_listen_port code.
It can be useful to have the build folder available so zip it up for
download as an artifact.
Although the 7z has an exclude for the installer exe it doesn't seem to
be working.
