fix(cli): set current working directory before scaffolded npm init

[bmuenzenmeyer]

Closes #1142

Summary of changes:

In my testing of production, running npm init patternlab prompts you to choose a directory,

If you choose to specify a directory (assuming to create a new one, in this case, we check for the presence of a package.json but then don't use that same path to run npm init if one is not found. Sure enough, the package.json is created in the calling directory, not the new one.

This change Attempts to set current working directory prior to project init.

I tried getting the scaffold tests to work but could not in limited time.

[coveralls]

Coverage remained the same at 73.406% when pulling 5993ebb on new-dir-init into aef661a on dev.