d:\git\Travel>npm install vuex --save
npm WARN optional SKIPPING OPTIONAL DEPENDENCY: fsevents@1.2.4 (node_modules\fsevents):
npm WARN notsup SKIPPING OPTIONAL DEPENDENCY: Unsupported platform for fsevents@1.2.4: wanted {“os”:“darwin”,“arch”:“any”} (current: {“os”:“win32”,“arch”:“x64”})

• vuex@3.1.0
  added 1 package from 1 contributor and audited 11127 packages in 17.479s
  found 2 vulnerabilities (1 moderate, 1 high)
  run npm audit fix to fix them, or npm audit for details

d:\git\Travel>npm audit fix
npm WARN optional SKIPPING OPTIONAL DEPENDENCY: fsevents@1.2.4 (node_modules\fsevents):
npm WARN notsup SKIPPING OPTIONAL DEPENDENCY: Unsupported platform for fsevents@1.2.4: wanted {“os”:“darwin”,“arch”:“any”} (current: {“os”:“win32”,“arch”:“x64”})

up to date in 11.408s
fixed 0 of 2 vulnerabilities in 11127 scanned packages
2 package updates for 2 vulns involved breaking changes
(use npm audit fix --force to install breaking changes; or refer to npm audit for steps to fix these manually)