Return error on Get(*Key).

service/datastore/datastore_test.go

Index: service/datastore/datastore_test.go
diff --git a/service/datastore/datastore_test.go b/service/datastore/datastore_test.go
index 2e3b7fa1ba5e922558f5ff0b52ccfef76a18b38d..0ca5c3f94be2dcdf090d5913e7da8681437d212b 100644
--- a/service/datastore/datastore_test.go
+++ b/service/datastore/datastore_test.go
@@ -410,6 +410,10 @@ func TestPut(t *testing.T) {
 				So(ds.Put(cs), ShouldErrLike, "invalid Put input type")
 			})
 
+			Convey("get with *Key is an error", func() {
+				So(ds.Get(&Key{}), ShouldErrLike, "invalid Get input type: *datastore.Key")
+			})
+
 			Convey("struct with no $kind is an error", func() {
 				s := MGSWithNoKind{}
 				So(ds.Put(&s), ShouldErrLike, "unable to extract $kind")