Update version to 2018.10.0-alpha

Author: DonJayamanne

package.json

@@ -2,7 +2,7 @@
  "name": "python",
  "displayName": "Python",
  "description": "Linting, Debugging (multi-threaded, remote), Intellisense, code formatting, refactoring, unit tests, snippets, and more.",
- "version": "2018.9.0",
+ "version": "2018.10.0-alpha",
  "publisher": "ms-python",
  "author": {
  "name": "Microsoft Corporation"