chore(tsc-wrapped): bump version number to 4.0.0-beta.2

This was done in order for us to be able to publish tsc-wrapped as @next tag on npm.

The next step is to change the build scripts to version and release @angular/tsc-wrapped
together with all the other packages. I'll create an issue/PR for this.

modules/@angular/compiler-cli/package.json

@@ -9,7 +9,7 @@
     "ng-xi18n": "./src/extract_i18n.js"
   },
   "dependencies": {
-    "@angular/tsc-wrapped": "0.5.0",
+    "@angular/tsc-wrapped": "4.0.0-beta.2",
     "reflect-metadata": "^0.1.2",
     "minimist": "^1.2.0"
   },

tools/@angular/tsc-wrapped/package.json

@@ -1,6 +1,6 @@
 {
   "name": "@angular/tsc-wrapped",
-  "version": "0.5.0",
+  "version": "4.0.0-beta.2",
   "description": "Wraps the tsc CLI, allowing extensions.",
   "homepage": "https://github.com/angular/angular/tree/master/tools/tsc-wrapped",
   "bugs": "https://github.com/angular/angular/issues",