Framework: Refactor where the python version check happens.

Fixes issue #181.

volatility/framework/__init__.py

@@ -2,11 +2,20 @@
 # which is available at https://www.volatilityfoundation.org/license/vsl-v1.0
 #
 """Volatility 3 framework."""
+# Check the python version to ensure it's suitable
+# We currently require 3.5.3 since 3.5.1 has no typing.Type and 3.5.2 is broken for ''/delayed encapsulated types
+import sys
+
+required_python_version = (3, 5, 3)
+if (sys.version_info.major != required_python_version[0] or sys.version_info.minor < required_python_version[1] or
+    (sys.version_info.minor == required_python_version[1] and sys.version_info.micro < required_python_version[2])):
+    raise RuntimeError(
+        "Volatility framework requires python version {}.{}.{} or greater".format(*required_python_version))
+
 import importlib
 import inspect
 import logging
 import os
-import sys
 from typing import Any, Dict, Generator, List, Type, TypeVar
 
 from volatility.framework import constants, interfaces
@@ -116,12 +125,3 @@ def list_plugins() -> Dict[str, Type[interfaces.plugins.PluginInterface]]:
             plugin_name = plugin_name[len("volatility.plugins."):]
         plugin_list[plugin_name] = plugin
     return plugin_list
-
-
-# Check the python version to ensure it's suitable
-# We currently require 3.5.3 since 3.5.1 has no typing.Type and 3.5.2 is broken for ''/delayed encapsulated types
-required_python_version = (3, 5, 3)
-if (sys.version_info.major != required_python_version[0] or sys.version_info.minor < required_python_version[1] or
-    (sys.version_info.minor == required_python_version[1] and sys.version_info.micro < required_python_version[2])):
-    raise RuntimeError(
-        "Volatility framework requires python version {}.{}.{} or greater".format(*required_python_version))