Added version requirement.

Author: aparajita

README.md

@@ -16,6 +16,8 @@ Before installing this plugin, you must ensure that `pep8` is installed on your
    [sudo] pip-3.x install pep8
    ```
 
+**Note:** This plugin requires `pep8` 1.4.6 or later.
+
 ### Linter configuration
 In order for `pep8` to be executed by SublimeLinter, you must ensure that its path is available to SublimeLinter. Before going any further, please read and follow the steps in [“Finding a linter executable”](http://sublimelinter.readthedocs.org/en/latest/troubleshooting.html#finding-a-linter-executable) through “Validating your PATH” in the documentation.
 

linter.py

@@ -21,6 +21,9 @@ class PEP8(PythonLinter):
 
     syntax = ('python', 'python django')
     cmd = ('pep8@python', '*', '-')
+    version_args = '--version'
+    version_re = r'(?P<version>\d+\.\d+\.\d+)'
+    version_requirement = '>= 1.4.6'
     regex = r'^.+?:(?P<line>\d+):(?P<col>\d+): (?:(?P<error>E)|(?P<warning>W))\d+ (?P<message>.+)'
     multiline = True
     defaults = {