Remove support for end-of-life Python 2.7 (#1318)

Remove support for end-of-life Python 2.7

Python 2.7 is end of life. It is no longer receiving bug fixes,
including for security issues. Python 2.7 went EOL on 2020-01-01. For
additional details on support Python versions, see:

Supported: https://devguide.python.org/#status-of-python-branches
EOL: https://devguide.python.org/devcycle/#end-of-life-branches

Removing support for EOL Pythons will reduce testing and maintenance
resources while allowing the library to move towards a modern Python 3
style. Python 2.7 users can continue to use the previous version of
redis-py.

Was able to simplify the code:

- Removed redis._compat module
- Removed __future__ imports
- Removed object from class definition (all classes are new style)
- Removed long (Python 3 unified numeric types)
- Removed deprecated __nonzero__ method
- Use simpler Python 3 super() syntax
- Use unified OSError exception
- Use yield from syntax

Co-authored-by: Andy McCurdy <andy@andymccurdy.com>

1 files changed, 1 insertions, 2 deletions

diff --git a/tox.ini b/tox.ini
index d1d97f4..c783bf0 100644
--- a/tox.ini
+++ b/tox.ini
@@ -3,12 +3,11 @@ addopts = -s
 
 [tox]
 minversion = 2.4
-envlist = {py27,py35,py36,py37,py38,pypy,pypy3}-{plain,hiredis}, flake8, covreport, codecov
+envlist = {py35,py36,py37,py38,pypy3}-{plain,hiredis}, flake8, covreport, codecov
 
 [testenv]
 deps =
     coverage
-    mock
     pytest >= 2.7.0
 extras =
     hiredis: hiredis