Remove http-beta dependency (#1806)

Author: brianquinlan

pkgs/cronet_http/example/pubspec.yaml

@@ -29,9 +29,3 @@ dev_dependencies:
 
 flutter:
   uses-material-design: true
-
-# TODO(brianquinlan): Remove this when a release version of `package:http`
-# supports abortable requests.
-dependency_overrides:
-  http:
-    path: ../../http/

pkgs/cronet_http/pubspec.yaml

@@ -11,7 +11,7 @@ environment:
 dependencies:
   flutter:
     sdk: flutter
-  http: ^1.5.0-beta
+  http: ^1.5.0
   http_profile: ^0.1.0
   jni: ^0.14.2
 

pkgs/cupertino_http/pubspec.yaml

@@ -14,7 +14,7 @@ dependencies:
   ffi: ^2.1.0
   flutter:
     sdk: flutter
-  http: ^1.5.0-beta
+  http: ^1.5.0
   http_profile: ^0.1.0
   objective_c: ^7.0.0
   web_socket: '>=0.1.5 <2.0.0'