* 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
Introduce a plugin that automates the process of completing a dns-01 challenge by creating, and subsequently removing, TXT records using RFC 2136 Dynamic Updates (a.k.a. nsupdate).
This plugin has been tested with BIND, but may work with other RFC 2136-compatible DNS servers, such as PowerDNS.