Fix depcheck's in Windows (#1320)
Fix depcheck's in Windows (#1320)

Both of the depcheck's are throwing errors

OS: `Windows 10`
Node: `v8.7.0`

Current Output:
```cmd
npm run frontend-depcheck

> gh-badges@1.3.0 frontend-depcheck C:\Users\Dan\Documents\GitHub\shields
> check-node-version --node '>= 8.0'

C:\Users\Dan\Documents\GitHub\shields\node_modules\semver\semver.js:678
    throw new TypeError('Invalid comparator: ' + comp);
    ^

TypeError: Invalid comparator: '
    at Comparator.parse (C:\Users\Dan\Documents\GitHub\shields\node_modules\semver\semver.js:678:11)
    at new Comparator (C:\Users\Dan\Documents\GitHub\shields\node_modules\semver\semver.js:662:8)
    at C:\Users\Dan\Documents\GitHub\shields\node_modules\semver\semver.js:828:12
    at Array.map (<anonymous>)
    at Range.parseRange (C:\Users\Dan\Documents\GitHub\shields\node_modules\semver\semver.js:827:13)
    at Range.<anonymous> (C:\Users\Dan\Documents\GitHub\shields\node_modules\semver\semver.js:769:17)
    at Array.map (<anonymous>)
    at new Range (C:\Users\Dan\Documents\GitHub\shields\node_modules\semver\semver.js:768:40)
    at C:\Users\Dan\Documents\GitHub\shields\node_modules\check-node-version\index.js:119:32
    at module.exports (C:\Users\Dan\Documents\GitHub\shields\node_modules\map-values\index.js:9:18)

npm ERR! Windows_NT 10.0.16299
npm ERR! argv "C:\\Program Files\\nodejs\\node.exe" "C:\\Users\\Dan\\AppData\\Roaming\\npm\\node_modules\\npm\\bin\\npm-cli.js" "run" "frontend-depcheck"
npm ERR! node v8.7.0
npm ERR! npm  v4.3.0
npm ERR! code ELIFECYCLE
npm ERR! errno 1
npm ERR! gh-badges@1.3.0 frontend-depcheck: `check-node-version --node '>= 8.0'`
npm ERR! Exit status 1
npm ERR!
npm ERR! Failed at the gh-badges@1.3.0 frontend-depcheck script 'check-node-version --node '>= 8.0''.
npm ERR! Make sure you have the latest version of node.js and npm installed.
npm ERR! If you do, this is most likely a problem with the gh-badges package,
npm ERR! not with npm itself.
npm ERR! Tell the author that this fails on your system:
npm ERR!     check-node-version --node '>= 8.0'
npm ERR! You can get information on how to open an issue for this project with:
npm ERR!     npm bugs gh-badges
npm ERR! Or if that isn't available, you can get their info via:
npm ERR!     npm owner ls gh-badges
npm ERR! There is likely additional logging output above.

npm ERR! Please include the following file with any support request:
npm ERR!     C:\Users\Dan\AppData\Roaming\npm-cache\_logs\2017-12-04T00_30_04_974Z-debug.log
```

```cmd
npm run server-depcheck

> gh-badges@1.3.0 server-depcheck C:\Users\Dan\Documents\GitHub\shields
> check-node-version --node '>= 6.0 < 9.0'

The system cannot find the file specified.

npm ERR! Windows_NT 10.0.16299
npm ERR! argv "C:\\Program Files\\nodejs\\node.exe" "C:\\Users\\Dan\\AppData\\Roaming\\npm\\node_modules\\npm\\bin\\npm-cli.js" "run" "server-depcheck"
npm ERR! node v8.7.0
npm ERR! npm  v4.3.0
npm ERR! code ELIFECYCLE
npm ERR! errno 1
npm ERR! gh-badges@1.3.0 server-depcheck: `check-node-version --node '>= 6.0 < 9.0'`
npm ERR! Exit status 1
npm ERR!
npm ERR! Failed at the gh-badges@1.3.0 server-depcheck script 'check-node-version --node '>= 6.0 < 9.0''.
npm ERR! Make sure you have the latest version of node.js and npm installed.
npm ERR! If you do, this is most likely a problem with the gh-badges package,
npm ERR! not with npm itself.
npm ERR! Tell the author that this fails on your system:
npm ERR!     check-node-version --node '>= 6.0 < 9.0'
npm ERR! You can get information on how to open an issue for this project with:
npm ERR!     npm bugs gh-badges
npm ERR! Or if that isn't available, you can get their info via:
npm ERR!     npm owner ls gh-badges
npm ERR! There is likely additional logging output above.

npm ERR! Please include the following file with any support request:
npm ERR!     C:\Users\Dan\AppData\Roaming\npm-cache\_logs\2017-12-04T00_32_13_243Z-debug.log
```

Looks like its due to `'` being used around the version rather than `"`.

This PR Output:
```cmd
npm run frontend-depcheck

> gh-badges@1.3.0 frontend-depcheck C:\Users\Dan\Documents\GitHub\shields
> check-node-version --node ">= 8.0"
```
```cmd
npm run server-depcheck

> gh-badges@1.3.0 server-depcheck C:\Users\Dan\Documents\GitHub\shields
> check-node-version --node ">= 6.0 < 9.0"
```
badges/shields,badges/shields,badges/shields