refactor: remove babel config files

packages/upgrade/.babelrc

@@ -1,21 +0,0 @@
-
-{
-  "presets": ["es2015"],
-  "plugins": [["transform-es2015-modules-umd", {
-    "globals": {
-      "@angular/core": "ng.core",
-      "@angular/common": "ng.common",
-      "@angular/compiler": "ng.compiler",
-      "@angular/platform-browser": "ng.platformBrowser",
-      "@angular/platform-browser-dynamic": "ng.platformBrowserDynamic",
-      "@angular/upgrade": "ng.upgrade",
-      "rxjs/Subject": "Rx",
-      "rxjs/observable/PromiseObservable": "Rx",  // this is wrong, but this stuff has changed in rxjs
-                                                  // b.6 so we need to fix it when we update.
-      "rxjs/operator/toPromise": "Rx.Observable.prototype",
-      "rxjs/Observable": "Rx"
-    },
-    "exactGlobals": true
-  }]],
-  "moduleId": "@angular/upgrade"
-}

packages/upgrade/.babelrc-static

@@ -1,12 +0,0 @@
-
-{
-  "presets": ["es2015"],
-  "plugins": [["transform-es2015-modules-umd", {
-    "globals": {
-      "@angular/upgrade": "ng.upgrade",
-      "@angular/upgrade/static": "ng.upgrade.static"
-    },
-    "exactGlobals": true
-  }]],
-  "moduleId": "@angular/upgrade/static"
-}