added package-lock.json

CHANGELOG.md

@@ -1,6 +1,7 @@
 # Changelog
 
 ## Draft
+- Added package-lock.json. [#1441](https://github.com/bigcommerce/cornerstone/pull/1441)
 
 ## 3.2.0 (2019-02-05)
 - Align product thumbnail image slider arrows. [#1399](https://github.com/bigcommerce/cornerstone/pull/1399)

README.md

@@ -102,6 +102,11 @@ and run:
 npm install
 ```
 
+Note: package-lock.json file was generated by Node version 8 and npm version 6.4.1. Although the app supports Node versions 6 and 8 as well as multiple versions of npm, we should always use those versions when updating package-lock.json, unless it is decided to upgrade those, and in this case the readme should be updated as well. If using a different version for node OR npm, please delete the package-lock.json file prior to installing node packages and also prior to pushing to github.
+
+If updating or adding a dependency, please double check that you are working on Node version 8 and npm version 6.4.1 and run ```npm update <package_name>```  or ```npm install <package_name>``` (avoid running npm install for updating a package). After updating the package, please make sure that the changes in the package-lock.json reflect only the updated/new package prior to pushing the changes to github.
+
+
 ### Icons
 Icons are delivered via a single SVG sprite, which is embedded on the page in
 `templates/layout/base.html`. It is generated via a grunt task `grunt svgstore`.