chore(deps): update dependency @types/node to v9.6.8

Author: renovate-bot

package.json

@@ -22,7 +22,7 @@
   },
   "devDependencies": {
     "@types/graphql": "0.13.0",
-    "@types/node": "9.6.7",
+    "@types/node": "9.6.8",
     "typescript": "2.8.3"
   },
   "repository": {

yarn.lock

@@ -10,7 +10,11 @@
   version "0.13.0"
   resolved "https://registry.yarnpkg.com/@types/graphql/-/graphql-0.13.0.tgz#78a33a7f429a06a64714817d9130d578e0f35ecb"
 
-"@types/node@9.6.7", "@types/node@^9.4.6":
+"@types/node@9.6.8":
+  version "9.6.8"
+  resolved "https://registry.yarnpkg.com/@types/node/-/node-9.6.8.tgz#32e3d3ef9ea285caeec70a05ab157847920a3fe4"
+
+"@types/node@^9.4.6":
   version "9.6.7"
   resolved "https://registry.yarnpkg.com/@types/node/-/node-9.6.7.tgz#5f3816d1db2155edcde1b2e3aa5d0e5c520cb564"