How do I de-link the ring volume and notification volume on my Droid Turbo

[AC Question]

I have a Droid Turbo that just upgraded to version 6.0.1, and as a result I can no longer separately control my ring volume and notification volume. I am on call at night and need to be able to receive phone calls but do NOT want to be notified when I get a text. I have no problem with turning off my wifi and data usage at night to eliminate other notifications, but how do I turn off the text notification volume while leaving my phone ringer on?