Add Test for PatchLink for create == false

[bonedaddy]

While writing this test, it became apparent that whether or not you create intermediary nodes, the resulting root hash is the same. What exactly is the effect of creating/not-creating the intermediary nodes? If there is a big difference I should be able to expand the test to check whether or not the intermediary nodes were created, however I'm not quite able to ascertain what the difference is.

Adds a test for pull/143

[Stebalien]

When create is passed, IPFS will automatically create intermediate merkledag objects. For example, the following won't work without --create

EMPTY=$(ipfs object new unixfs-dir)
ipfs object patch add-link --create $EMPTY a/b/c $EMPTY

(we should probably improve docs but, really, we're planning on deprecating the "object" APIs anyways in favor of the more general dag APIs).

[bonedaddy]

Ah okay that makes sense, thanks for the response, i've updated the tests accordingly. I do like the sound of working with the dag APIs a lot more 😁

[Stebalien]

Thanks!