Move shared caching logic to public location, rename to DiffMigrateLayer

commons/src/layer.rs

@@ -1,5 +1,14 @@
 mod configure_env_layer;
 mod default_env_layer;
 
+#[deprecated(
+    since = "0.0.0",
+    note = "Use the struct layer API in the latest libcnb.rs instead"
+)]
 pub use self::configure_env_layer::ConfigureEnvLayer;
+
+#[deprecated(
+    since = "0.0.0",
+    note = "Use the struct layer API in the latest libcnb.rs instead"
+)]
 pub use self::default_env_layer::DefaultEnvLayer;

commons/src/lib.rs

@@ -2,10 +2,6 @@ pub mod cache;
 pub mod display;
 pub mod gem_version;
 pub mod gemfile_lock;
-#[deprecated(
-    since = "0.0.0",
-    note = "Use the struct layer API in the latest libcnb.rs instead"
-)]
 pub mod layer;
 pub mod metadata_digest;
 pub mod output;