Crates io (#76)

* crates re-organisation

* fixed typo in layout & added test for vmp_apply

* updated dependencies

poulpy-hal/src/layouts/scratch.rs

@@ -0,0 +1,13 @@
+use std::marker::PhantomData;
+
+use crate::layouts::Backend;
+
+pub struct ScratchOwned<B: Backend> {
+    pub data: Vec<u8>,
+    pub _phantom: PhantomData<B>,
+}
+
+pub struct Scratch<B: Backend> {
+    pub _phantom: PhantomData<B>,
+    pub data: [u8],
+}