Generated client/package.json creates production builds using webpack by default

[serodriguez68]

WORK DONE

1. The package.json file created by the generator now creates minified javascript production builds by default. This was done by adding the -p flag to webpack on the build:production script.
2. A test was added to verify that the build:production script includes the -p flag.

NOTES

1. I deleted the previous PR and created a new one because I squashed and rebased to keep the project history clean.
2. Sorry for the delay, it took me a while to wrap my head around the development setup and the codebase.

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This change is 

[justin808]

Thanks @serodriguez68

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Reviewed 3 of 3 files at r1.
Review status: all files reviewed at latest revision, all discussions resolved.

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