fix vulnerabilities in dependencies

[micahstubbs]

found 825 vulnerabilities (764 low, 45 moderate, 14 high, 2 critical)
run npm audit fix to fix them, or npm audit for details

steps to reproduce

node -v
# v8.12.0
npm -v
# v6.4.1

npm install

text

➜  blockbuilder git:(master) npm install
> node-sass@4.9.3 install /home/ubuntu/blockbuilder/node_modules/node-sass
> node scripts/install.js
Downloading binary from https://github.com/sass/node-sass/releases/download/v4.9.3/linux-x64-57_binding.node
Download complete..] - :
Binary saved to /home/ubuntu/blockbuilder/node_modules/node-sass/vendor/linux-x64-57/binding.node
Caching binary to /home/ubuntu/.npm/node-sass/4.9.3/linux-x64-57_binding.node
> node-sass@4.9.3 postinstall /home/ubuntu/blockbuilder/node_modules/node-sass
> node scripts/build.js
Binary found at /home/ubuntu/blockbuilder/node_modules/node-sass/vendor/linux-x64-57/binding.node
Testing binary
Binary is fine
npm WARN optional SKIPPING OPTIONAL DEPENDENCY: fsevents@1.0.14 (node_modules/webpack/node_modules/watchpack/node_modules/chokidar/node_modules/
fsevents):
npm WARN notsup SKIPPING OPTIONAL DEPENDENCY: Unsupported platform for fsevents@1.0.14: wanted {"os":"darwin","arch":"any"} (current: {"os":"lin
ux","arch":"x64"})
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":"linu
x","arch":"x64"})
added 2280 packages from 626 contributors and audited 15075 packages in 60.844s
found 825 vulnerabilities (764 low, 45 moderate, 14 high, 2 critical)
  run `npm audit fix` to fix them, or `npm audit` for details

[LoganDark]

facebook/create-react-app#11174

TL;DR npm audit is fundamentally broken and should not be used. I know I'm 4 years late, but just so you know