Update npm packages to latest versions for 6.4 Beta 1 (attempt 2)#5311

mikachan wants to merge 11 commits intoWordPress:trunkWordPress/wordpress-develop:trunkfrom

mikachan:package-updates-6.4-beta-1-v2mikachan/wordpress-develop:package-updates-6.4-beta-1-v2Copy head branch name to clipboard