Update dependency typescript to v3

Author: renovate-bot

package.json

@@ -20,7 +20,7 @@
     "now": "9.3.3",
     "npm-run-all": "4.1.5",
     "ts-node": "4.1.0",
-    "typescript": "2.9.2"
+    "typescript": "3.4.2"
   },
   "dependencies": {
     "apollo-errors": "1.9.0",

yarn.lock

@@ -2573,9 +2573,10 @@ type-is@~1.6.16:
     media-typer "0.3.0"
     mime-types "~2.1.18"
 
-typescript@2.9.2:
-  version "2.9.2"
-  resolved "https://registry.yarnpkg.com/typescript/-/typescript-2.9.2.tgz#1cbf61d05d6b96269244eb6a3bce4bd914e0f00c"
+typescript@3.4.2:
+  version "3.4.2"
+  resolved "https://registry.yarnpkg.com/typescript/-/typescript-3.4.2.tgz#9ed4e6475d906f589200193be056f5913caed481"
+  integrity sha512-Og2Vn6Mk7JAuWA1hQdDQN/Ekm/SchX80VzLhjKN9ETYrIepBFAd8PkOdOTK2nKt0FCkmMZKBJvQ1dV1gIxPu/A==
 
 undefsafe@^2.0.2:
   version "2.0.2"