Fixes #1030. Add support for alpha versions of autopep8

See https://github.com/Glavin001/atom-beautify/issues/1030#issuecomment-309371093

CHANGELOG.md

@@ -1,4 +1,5 @@
 # Next
+- Fixes [#1030](https://github.com/Glavin001/atom-beautify/issues/1030). Add support for alpha versions of autopep8
 - Fixes [#1725](https://github.com/Glavin001/atom-beautify/issues/1725). Fix version parsing of PHP executable
 - Fixes [#1730](https://github.com/Glavin001/atom-beautify/issues/1730). Correctly parse PHPCBF version and improve handling of Executable
 - ...

src/beautifiers/autopep8.coffee

@@ -16,7 +16,11 @@ module.exports = class Autopep8 extends Beautifier
       homepage: "https://github.com/hhatto/autopep8"
       installation: "https://github.com/hhatto/autopep8#installation"
       version: {
-        parse: (text) -> text.match(/autopep8 (\d+\.\d+\.\d+)/)[1]
+        parse: (text) ->
+          try
+            text.match(/autopep8 (\d+\.\d+\.\d+)/)[1]
+          catch
+            text.match(/autopep8 (\d+\.\d+)/)[1] + ".0"
         runOptions: {
           returnStdoutOrStderr: true
         }