Edit collection (#173)

* Collection edit modal

* Add icon

* 💚

* Oh look, some specs

* Delete collection

* Remove from collection

* Handle error responses
Protect against deleting last collection

* Fix key

* 💚

* Keyboard navigate documents list

* Add missing database constraints

frontend/scenes/CollectionEdit/index.js

@@ -0,0 +1,3 @@
+// @flow
+import CollectionEdit from './CollectionEdit';
+export default CollectionEdit;