fix(npm): updated minimal version of angular 2 to beta 10

BREAKING CHANGES: because of recent changes we have to use RxJS >= beta 2 and that means a recent version of Angular 2. You now have to upgrade to Angular beta 10 or more to use ng2-translate.

Fixes #74

package.json

@@ -27,11 +27,11 @@
   "typings": "./ng2-translate.d.ts",
   "homepage": "https://github.com/ocombe/ng2-translate",
   "peerDependencies": {
-    "angular2": ">= 2.0.0-beta.0",
+    "angular2": ">= 2.0.0-beta.10",
     "es6-shim": ">= 0.33.3",
     "reflect-metadata": ">= 0.1.2",
-    "rxjs": ">= 5.0.0-beta.0",
-    "zone.js": ">= 0.5.10"
+    "rxjs": ">= 5.0.0-beta.2",
+    "zone.js": ">= 0.6.4"
   },
   "devDependencies": {
     "angular2": "2.0.0-beta.12",