npm update [<pkg> [<pkg> ...]]
This command will update all the packages listed to the latest version
(specified by the tag config), as well as updating any dependent
packages to use the new version, if possible.
Additionally, it will activate the new version, and delete any old versions, if safe to do so
If the update-dependents configuration parameter is set to "true", then
packages will always be updated when they are installed, if they are the newest
version.
If the update-dependents configuration parameter is set to "always", then
packages will be updated when they are installed, even if to do so would be a
downgrade.