Need a story for locally testing npm pack

[rgerd]

(#200) introduced a change to the @babylon/react-native and @babylon/react-native-windows npm modules. Every change to the modules also changes their checksums (see 7ca1e79), and without revving the version number, npm install will fail in the PackageTest apps, because the checksum stored in the package-lock.json doesn't match for "version 0.0.1". This is to be expected, and will occur for any changes made to our npm packages.

I'm open to other suggestions, but I think the best way to fix this would be:
Delete + gitignore the package-lock.json files in the PackageTest apps, and write documentation that says to install modules in the PackageTest app with npm install --no-package-lock.

[ryantrem]

I’ve always just done an npm uninstall @babylonjs/react-native and then reinstall with the locally built package path, though I don’t think this is documented. Will this work for you?

[ryantrem]

We could automate this with another gulp command for the package as well.