Remove nb/oxymel dependency, which has moved to the package

Author: danielbachhuber

composer.json

@@ -30,7 +30,6 @@
 		"symfony/event-dispatcher": "~2.7",
 		"symfony/process": "~2.1",
 		"symfony/translation": "~2.7",
-		"nb/oxymel": "~0.1.0",
 		"composer/composer": "^1.2.0",
 		"wp-cli/cron-command": "^1.0",
 		"wp-cli/import-command": "^1.0",