explicitly depend on the mojom package

sky/sdk/packages/sky/pubspec.yaml

diff --git a/sky/sdk/packages/sky/pubspec.yaml b/sky/sdk/packages/sky/pubspec.yaml
index 12f7faf..8004c41 100644
--- a/sky/sdk/packages/sky/pubspec.yaml
+++ b/sky/sdk/packages/sky/pubspec.yaml
@@ -5,3 +5,4 @@
 version: 0.0.5
 dependencies:
   mojo: '>=0.0.1 <1.0.0'
+  mojom: '>=0.0.3 <0.1.0'