Fix Python 2/3 compatibility issues

- version bump 0.3.12
- upgrade `six, flake8` libs
- fix `flake8` check issues
- add import of `from __future__ import print_function`
- fix params for `zsocket.setsockopt()` and `hashlib.sha1()` methods
- use `range, map` functions from `six`
- wrap result of `map, dict.keys(), dict.values()` functions in a list
- fix `EMQdeque.__unicode__()` method for py2 support
- fix using of exception messages
- update integer division for support the same behavior in py3 as is in py2
- refactor using of `filter` function

1 files changed, 4 insertions, 4 deletions

diff --git a/setup.py b/setup.py
index b4adf1d..3bcbc4c 100644
--- a/setup.py
+++ b/setup.py
@@ -20,7 +20,7 @@ setup(
     packages=find_packages(),
     install_requires=[
         'pyzmq==18.1.0',
-        'six==1.10.0',
+        'six==1.14.0',
         'monotonic==0.4',
         'croniter==0.3.10',
         'future==0.15.2',
@@ -29,9 +29,9 @@ setup(
     extras_require={
           'docs': ['Sphinx==1.5.2', ],
           'testing': [
-              'flake8==3.2.1',
-              'flake8-import-order==0.11',
-              'flake8-print==2.0.2',
+              'flake8==3.7.8',
+              'flake8-import-order==0.18.1',
+              'flake8-print==3.1.0',
               'coverage==4.0.3',
               'testfixtures==4.7.0',
               'freezegun==0.3.7',