Chore: Set latest TS version

README.md

@@ -8,7 +8,7 @@ A parser that converts TypeScript source code into an [ESTree](https://github.co
 
 We will always endeavor to support the latest stable version of TypeScript.
 
-The version of TypeScript currently supported by this parser is `~2.8.1`. This is reflected in the `devDependency` requirement within the package.json file, and it is what the tests will be run against. We have an open `peerDependency` requirement in order to allow for experimentation on newer/beta versions of TypeScript.
+The version of TypeScript currently supported by this parser is `~2.9.1`. This is reflected in the `devDependency` requirement within the package.json file, and it is what the tests will be run against. We have an open `peerDependency` requirement in order to allow for experimentation on newer/beta versions of TypeScript.
 
 If you use a non-supported version of TypeScript, the parser will log a warning to the console.
 

package.json

@@ -31,7 +31,7 @@
     "npm-license": "0.3.3",
     "shelljs": "0.8.1",
     "shelljs-nodecli": "0.1.1",
-    "typescript": "2.9.0-dev.20180421"
+    "typescript": "~2.9.1"
   },
   "keywords": [
     "ast",