[Security] Bump acorn from 6.2.0 to 6.4.2#50

dependabot-preview[bot] wants to merge 1 commit intomasterjimcli/logger:masterfrom

dependabot/npm_and_yarn/acorn-6.4.2jimcli/logger:dependabot/npm_and_yarn/acorn-6.4.2Copy head branch name to clipboard