Drop support for EOL Python 2.6 and 3.3

* 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

certbot/main.py

@@ -4,7 +4,6 @@ import functools
 import logging.handlers
 import os
 import sys
-import warnings
 
 import configobj
 import josepy as jose
@@ -1218,17 +1217,6 @@ def main(cli_args=sys.argv[1:]):
         # Let plugins_cmd be run as un-privileged user.
         if config.func != plugins_cmd:
             raise
-    deprecation_fmt = (
-        "Python %s.%s support will be dropped in the next "
-        "release of Certbot - please upgrade your Python version.")
-    # We use the warnings system for Python 2.6 and logging for Python 3
-    # because DeprecationWarnings are only reported by default in Python <= 2.6
-    # and warnings can be disabled by the user.
-    if sys.version_info[:2] == (2, 6):
-        warning = deprecation_fmt % sys.version_info[:2]
-        warnings.warn(warning, DeprecationWarning)
-    elif sys.version_info[:2] == (3, 3):
-        logger.warning(deprecation_fmt, *sys.version_info[:2])
 
     set_displayer(config)