`--no-warp-drive` config when the option isn't used

[Windvis]

It seems that generating an app without passing any arguments adds the --no-warp-drive option to the ember-cli-update.json file which means any future updates will use the incorrect flags.

This logic seems wrong:

ember-app-blueprint/index.js

Line 84 in 2caac55

!options.warpDrive && `"--no-warp-drive"`,

Also, do we still want to output the --no-ember-data option? I assume we only want --no-warp-drive or no option at all at the moment?

This adds a failing test: #272