Installed Revisioning Module, how do you make it default to create new revision? I just installed the Revisioning module, but all my existing nodes are set to: "Modify current revision, no moderation", but I would like it to be set as create new revision by default. I don't want my users to manually click this when they are editing a node. 

How do I make it by default to create a new revision for existing nodes?

Creating new nodes is not an issue as its already set by default to create a new revision.
You can alter the node edit form following the Revisioning's implementation.

/**
 * Implements hook_form_alter().
 */
function myModule_form_alter(&amp;$form, &amp;$form_state, $form_id) {
  if (!empty($form['#node_edit_form'])) {
    if (isset($form['revision_information']['revision_operation'])) {
      $form['revision_information']['revision_operation']['#default_value'] = REVISIONING_NEW_REVISION_NO_MODERATION;
    }
  }
}

/**
 * Implements HOOK_module_implements_alter().
 *
 * Ensure our hook runs after revisioning_form_alter().
 */
function myModule_module_implements_alter(&amp;$implementations, $hook) {
  if ($hook == 'form_alter') {
    $group = $implementations['myModule'];
    unset($implementations['myModule']);
    $implementations['myModule'] = $group;
  }
}