This command removes "extraneous" packages. If a package name is
provided, then only packages matching one of the supplied names are
Extraneous packages are packages that are not listed on the parent
packages dependencies list.
If the --production flag is specified or the NODE_ENV environment
variable is set to production, this command will remove the packages
specified in your devDependencies. Setting --production=false will
negate NODE_ENV being set to production.