fix(tsconfig): add "exclude" property to aot config

The "exclude" property isn't properly inherited from the base
configuration ("tsconfig.json") so we need to explicitly specify it.
This caused the angular compiler to try to parse the `platforms` folder
and eventually fail.

fixes #101

Author: sis0k0

Diff for: tsconfig.aot.json.template

@@ -27,6 +27,10 @@
       "globals": ["node_modules/tns-core-modules/globals"]
     }
   },
+  "exclude": [
+    "node_modules",
+    "platforms"
+  ],
   "angularCompilerOptions": {
     "skipMetadataEmit": true,
     "genDir": "./"