chore(deps): update dependency typescript to v2.8.1

Author: renovate-bot

package.json

@@ -23,7 +23,7 @@
   "devDependencies": {
     "@types/graphql": "0.12.6",
     "@types/node": "9.6.0",
-    "typescript": "2.7.2"
+    "typescript": "2.8.1"
   },
   "repository": {
     "type": "git",

yarn.lock

@@ -90,9 +90,9 @@ node-fetch@2.1.1:
   version "2.1.1"
   resolved "https://registry.yarnpkg.com/node-fetch/-/node-fetch-2.1.1.tgz#369ca70b82f50c86496104a6c776d274f4e4a2d4"
 
-typescript@2.7.2:
-  version "2.7.2"
-  resolved "https://registry.yarnpkg.com/typescript/-/typescript-2.7.2.tgz#2d615a1ef4aee4f574425cdff7026edf81919836"
+typescript@2.8.1:
+  version "2.8.1"
+  resolved "https://registry.yarnpkg.com/typescript/-/typescript-2.8.1.tgz#6160e4f8f195d5ba81d4876f9c0cc1fbc0820624"
 
 uuid@^3.1.0:
   version "3.1.0"