Fixind defaults.yml

[insspb]

This fix will:
Moving from static worker process to ansible selected. Values is based on nginx recommendations.
Defaults file quotes fix.

I have travis error on source download while testing. This is not related to particular change.

[soupdiver]

Hmmm this adds complexity to the configuration because of all these implicit values. Probably it's a good idea to have as many workers as cores but it's implicit and on different systems this causes different configurations even if you don't change anything.

As always this has pros and cons.

What's your opinion about flexibility vs. easyness @otakup0pe @pjan @farridav ?

[insspb]

You can always change this value in defaults or in host settings,
but let's be real how many virtual pc's are with 4 cores (current config) inside on deploy?
And as the other side, when you scale up virtual pc or server with my config you do not need to think about reconfiguration. It will be done by ansible on run.

[soupdiver]

I know you can change the values all the time. It's more about simplicity and predictable behaviour.
Would like to get some feedback of the others before deciding on that