Temp fix for reported security vuln

[eritbh]

https://nvd.nist.gov/vuln/detail/CVE-2018-3728

$ yarn why hoek
yarn why v1.7.0
[1/4] Why do we have the module "hoek"...?
[2/4] Initialising dependency graph...
[3/4] Finding dependency...
[4/4] Calculating file sizes...
=> Found "[email protected]"
info Reasons this module exists
   - "node-sass#request#hawk" depends on it
   - Hoisted from "node-sass#request#hawk#hoek"
   - Hoisted from "node-sass#request#hawk#boom#hoek"
   - Hoisted from "node-sass#request#hawk#sntp#hoek"
info Disk size without dependencies: "212KB"
info Disk size with unique dependencies: "212KB"
info Disk size with transitive dependencies: "212KB"
info Number of shared dependencies: 0
Done in 1.93s.

sass/node-sass#2355 and sass/node-sass#2312

tl;dr revert d975ff6 when node-sass v5 drops