Pending tests for "complex" changeset generation

We need tests to cover all possible cases where `getComplexChange` is called - https://github.com/developmentseed/observe/blob/418fc71e5631fe3f3bc11740d70b8607ae10c694/app/utils/edit-to-osm-change.js#L50 :

Add way:
- [ ] Simple case of add way with all new nodes
- [ ] Add new node with one or more shared nodes to existing way
- [ ] Add node with one or more shared nodes to existing way and MOVE that node

Modify way:
- [ ] Move one or more nodes on way
- [ ] Add node to way
- [ ] Delete node from way
- [ ] Add node to way that is shared by another way
- [ ] Merge node on way with node on another way

cc @geohacker