Dependencies update : fix security issues

The 2.1.14 version [has some vulnerabilities](https://snyk.io/test/npm/phantomjs-prebuilt/2.1.14) that can be fixed by updating the npm dependencies.

This PR fixes :
* 1 *Uninitialized Memory Exposure* : updated `extract-zip@1.5.0` to version _1.6.5_
* 1 *Uninitialized Memory Exposure* : updated `request@2.79.0` to version _2.81.0_ ([change log](https://github.com/request/request/blob/master/CHANGELOG.md#v2810-20170309))

package.json

@@ -40,12 +40,12 @@
   },
   "dependencies": {
     "es6-promise": "~4.0.3",
-    "extract-zip": "~1.5.0",
+    "extract-zip": "~1.6.5",
     "fs-extra": "~1.0.0",
     "hasha": "~2.2.0",
     "kew": "~0.7.0",
     "progress": "~1.1.8",
-    "request": "~2.79.0",
+    "request": "~2.81.0",
     "request-progress": "~2.0.1",
     "which": "~1.2.10"
   },