Properly handle Git URLs with trailing slashes.

utils/pub/pubspec.dart

Index: utils/pub/pubspec.dart
diff --git a/utils/pub/pubspec.dart b/utils/pub/pubspec.dart
index 2b82a71acb76f4da67a83adda9a3d9865fbb724c..ca3ae9142f3f68d9087ed9bb1ed7f59902277abf 100644
--- a/utils/pub/pubspec.dart
+++ b/utils/pub/pubspec.dart
@@ -110,6 +110,13 @@ class Pubspec {
 
         source.validateDescription(description, fromLockFile: false);
 
+        var nameFromSource = source.packageName(description);
+        if (nameFromSource != name) {
+          throw new FormatException('The name you specified for your '
+              'dependency, "$name", doesn\'t match the name "$nameFromSource" '
+              '(from "$description").');
+        }
+
         dependencies.add(new PackageRef(
             source, versionConstraint, description));
       });