Vulnerability in tar dependency.

[csalmeida]

I've noticed that an npm package as been flagged as a security vulnerability. This poses no problems for anyone using the themes as they're pure .css.

This is a difficult error to fix as documented in the node-sass repo, but it is worth flagging.

                    === npm audit security report ===                        
                                                                                
┌──────────────────────────────────────────────────────────────────────────────┐
│                                Manual Review                                 │
│            Some vulnerabilities require your attention to resolve            │
│                                                                              │
│         Visit https://go.npm.me/audit-guide for additional guidance          │
└──────────────────────────────────────────────────────────────────────────────┘
┌───────────────┬──────────────────────────────────────────────────────────────┐
│ High          │ Arbitrary File Overwrite                                     │
├───────────────┼──────────────────────────────────────────────────────────────┤
│ Package       │ tar                                                          │
├───────────────┼──────────────────────────────────────────────────────────────┤
│ Patched in    │ >=4.4.2                                                      │
├───────────────┼──────────────────────────────────────────────────────────────┤
│ Dependency of │ gulp-sass [dev]                                              │
├───────────────┼──────────────────────────────────────────────────────────────┤
│ Path          │ gulp-sass > node-sass > node-gyp > tar                       │
├───────────────┼──────────────────────────────────────────────────────────────┤
│ More info     │ https://npmjs.com/advisories/803                             │
└───────────────┴──────────────────────────────────────────────────────────────┘
found 1 high severity vulnerability in 6938 scanned packages
  1 vulnerability requires manual review. See the full report for details.

[csalmeida]

Fixed with #20.