Update dependency typescript to v3.4.3

Author: renovate-bot

package.json

@@ -38,7 +38,7 @@
     "standard": "10.0.3",
     "ts-jest": "22.4.4",
     "tslint": "5.9.1",
-    "typescript": "3.0.3"
+    "typescript": "3.4.3"
   },
   "keywords": [
     "bot",

yarn.lock

@@ -4382,9 +4382,9 @@ typedarray@^0.0.6:
   version "0.0.6"
   resolved "https://registry.yarnpkg.com/typedarray/-/typedarray-0.0.6.tgz#867ac74e3864187b1d3d47d996a78ec5c8830777"
 
-typescript@3.0.3:
-  version "3.0.3"
-  resolved "https://registry.yarnpkg.com/typescript/-/typescript-3.0.3.tgz#4853b3e275ecdaa27f78fda46dc273a7eb7fc1c8"
+typescript@3.4.3:
+  version "3.4.3"
+  resolved "https://registry.yarnpkg.com/typescript/-/typescript-3.4.3.tgz#0eb320e4ace9b10eadf5bc6103286b0f8b7c224f"
 
 uglify-js@^2.6:
   version "2.8.29"