Remove unused packages

[gnikit]

From what I can tell a lot of npm packages are actually not used.
npx depcheck has identified the following packages as redundant.

npx: installed 146 in 9.08s
Unused devDependencies
* @types/fs-extra
* @types/glob
* @types/mocha
* decache
* fs-extra
* glob
* istanbul
* mocha
* remap-istanbul

Given that we do not actually make use of these packages anymore I suspect it should be okay to remove