Update socks-proxy-agent to v4.0.1 (#26)

Author: thisislawatts

package.json

@@ -36,7 +36,7 @@
     "lru-cache": "^4.1.2",
     "pac-proxy-agent": "^2.0.1",
     "proxy-from-env": "^1.0.0",
-    "socks-proxy-agent": "^3.0.0"
+    "socks-proxy-agent": "^4.0.1"
   },
   "devDependencies": {
     "mocha": "^5.0.5",