Device volume is very low on wake up

[krisgesling]

Describe the bug
Flagged in #44

To Reproduce
From @hariedo:

On the first try, "Hey, Mycroft. Wake up." I got "I am already awake" at my current volume, and no spurious fallback. Good.

Then I put it to sleep. And then wake it up. Barely audible message (I am awake now)and the face goes away. The volume is back down to a very low value, likely 0 or 1.

Then I tried to do "Hey, Mycroft. Wake up." I get a barely audible message (already awake), but also no spurious fallback as reported above.

Expected behavior
Device volume should not change by going to sleep unless user changes it via touch screen or volume button.