Removed package-lock.json from .gitignore
Removed package-lock.json from .gitignore

Removed package-lock.json from .gitignore

package-lock.json is intended to be checked into source control, without a package-lock.json using npm makes little sense over yarn. 

I see this was added in 2017, when there was an issue with the package-lock.json updating, this issue is now long resolved.
h5bp/html5-boilerplate,h5bp/html5-boilerplate,roblarsen/html5-boilerplate,roblarsen/html5-boilerplate,rprouse/html5-boilerplate,rprouse/html5-boilerplate