* Drop support for EOL Python 2.6
* Use more helpful assertIn/NotIn instead of assertTrue/False
* Drop support for EOL Python 3.3
* Remove redundant Python 3.3 code
* Restore code for RHEL 6 and virtualenv for Py2.7
* Revert pipstrap.py to upstream
* Merge py26_packages and non_py26_packages into all_packages
* Revert changes to *-auto in root
* Update by calling letsencrypt-auto-source/build.py
* Revert permissions for pipstrap.py
* Add tools/pip_constraints.txt to pin all Python dependencies
* Use tools/pip_constraints.txt in tools/pip_install.sh
* Install dnsmadeeasy extras in dnsmadeeasy plugin
Implement an Authenticator which can fulfill a dns-01 challenge using
the DNS Made Easy API. Applicable only for domains using DNS Made Easy.
Testing Done:
* `tox -e py27`
* `tox -e lint`
* Manual testing:
(`http://api.sandbox.dnsmadeeasy.com/V2.0` used as the
`api_endpoint` for all manual testing)
* Used `certbot certonly --dns-dnsmadeeasy -d`, specifying a
credentials file as a command line argument. Verified that a
certificate was successfully obtained without user interaction.
* Negative testing:
* Path to non-existent credentials file.
* Credentials file with unsafe permissions (644).
* Path to credentials file with an invalid API key.
* Path to credentials file with a malformed API key.
* Path to credentials file with an invalid Secret key.
* Path to credentials file with a malformed Secret key.
* Domain name not registered to DNS Made Easy account.
