Avoid hash updates in composer.lock

If you run composer update the hash in composer.lock gets updated only if the content of composer.json changed.
If you run composer drupal-update the hash always changes even if nothing changed regarding the dependencies. That's caused by the fact that you add a date in this line in composer.json:

"_generator": "Generated by composer_manager on 2015-08-21T17:12:20+02:00",

From my point of view the content of composer.json and composer.lock should not change until something in the dependencies changed for real!

I created a patch to remove the date from _generator. That eases deployments based on git a lot.Now you can composer drupal-update and files don't change until necessary.