chore: unpin rxjs versions

Author: sis0k0

Diff for: e2e/router/package.json

@@ -25,7 +25,7 @@
     "nativescript-angular": "file:../../nativescript-angular",
     "nativescript-intl": "^3.0.0",
     "reflect-metadata": "~0.1.8",
-    "rxjs": "5.5.2",
+    "rxjs": "^5.5.4",
     "tns-core-modules": "next",
     "zone.js": "^0.8.4"
   },

Diff for: ng-sample/package.json

@@ -42,7 +42,7 @@
     "@angular/platform-browser-dynamic": "~5.0.0",
     "@angular/router": "~5.0.0",
     "nativescript-angular": "file:../nativescript-angular",
-    "rxjs": "5.5.2",
+    "rxjs": "^5.5.2",
     "tns-core-modules": "next",
     "zone.js": "~0.8.2"
   },