Friendlier nuke script (#678)
Friendlier nuke script (#678)

* Use double-quotes in npm scripts because windows.
* Don't exit with error code if package-lock.json already present.
* lerna exec arguments are joined as a single string so need to wrap the whole bit to ensure the bash script is handed to bash as a whole string.
* Don't echo anything if package-lock present, to keep output clearer.
* Make the npm install use --package-lock-only
* Simplified nuke script without a bash -c

Polymer/tools,Polymer/tools,Polymer/tools,Polymer/tools