Added check python version and apdate version 1.2.3

Author: drobotun

HISTORY.rst

@@ -1,6 +1,10 @@
 Release History
 """""""""""""""
 
+.. rubric:: 1.2.3 (23.05.2020)
+
+- Added Python version checking (use version 3.6 or higher)
+
 .. rubric:: 1.2.2 (15.05.2020)
 
 - Fixed a MAC calculation bug when using padding in the **gostcipher** module (in earlier versions (including 1.2.1), the MAC with padding was calculated incorrectly (the bug was in the 'msb' and 'update' functions))
@@ -40,4 +44,4 @@ Release History
 
 .. rubric:: 1.0.0 (08.04.2020)
 
-- First release of **'gostcrypto'**
+- First release of **'gostcrypto'**

docs/source/intro.rst

@@ -372,6 +372,10 @@ Package source code: https://github.com/drobotun/gostcrypto
 Release History
 ~~~~~~~~~~~~~~~
 
+.. rubric:: 1.2.3 (23.05.2020)
+
+- Added Python version checking (use version 3.6 or higher)
+
 .. rubric:: 1.2.2 (15.05.2020)
 
 - Fixed a MAC calculation bug when using padding in the **gostcipher** module (in earlier versions (including 1.2.1), the MAC with padding was calculated incorrectly (the bug was in the 'msb' and 'update' functions))
@@ -410,4 +414,4 @@ Release History
 
 .. rubric:: 1.0.0 (08.04.2020)
 
-- First release of **'gostcrypto'**
+- First release of **'gostcrypto'**

gostcrypto/__init__.py

@@ -31,8 +31,15 @@
     https://github.com/drobotun/gostcrypto.
 """
 
+from sys import version_info
+from sys import exit as sys_exit
+
+if version_info.major < 3 or version_info.minor < 6:
+    print('Use python version 3.6 or higher')
+    sys_exit()
+
 __title__ = 'gostcrypto'
-__version__ = '1.2.2'
+__version__ = '1.2.3'
 __author__ = 'Evgeny Drobotun'
 __author_email__ = '[email protected]'
 __license__ = 'MIT'

setup.py

@@ -25,8 +25,8 @@
         'Development Status :: 4 - Beta',
         'Intended Audience :: Developers',
         'License :: OSI Approved :: MIT License',
-        'Programming Language :: Python :: 3.4',
-        'Programming Language :: Python :: 3.7',
+        'Programming Language :: Python :: 3.6',
+        'Programming Language :: Python :: 3.8',
     ],
     test_suite="tests",
     packages=find_packages()