Avoid creation of unwanted node_modules folder as part of test:autofix

[plopesc]

This is a followup from #223

When running task test:autofix, the unwanted node_modules folder is created and new execution of other tasks that checks the existence of this folder, like task sass:compile fail.

This can be mitigated removing manually the node_modules before executing the command, but this solution, avoids the folder generation

[justafish]

Thanks!