Disable autoupdates in WordPress 3.7+.

wp-config-no-autoupdates-example.php

<?php

# Disables all kind of file modifications: 
# core, plugins and themes won't be auto-updated
# and file editors won't appear anymore in wp-admin.
define( 'DISALLOW_FILE_MODS', true );

# Disables all core updates:
define( 'WP_AUTO_UPDATE_CORE', false );

# Enables all core updates, including minor and major:
//define( 'WP_AUTO_UPDATE_CORE', true );

# Enables core updates for minor releases (default):
//define( 'WP_AUTO_UPDATE_CORE', 'minor' );