Fixes for broken tox runs (#2053)

* order_utils.py: git rm package.json

This was used at one time, a long, long time ago, but is no longer used,
and its presence actually causes problems when trying to do, eg
`PKG=@0x/python-contract-wrappers yarn build` from within the
order_utils directory.

* order_utils.py: improve `./setup.py clean`

* python-packages: in tox, test, don't lint

* python-packages: update dev req's to fix tox runs

* contract_wrappers.py: post-publish version bump

python-packages/middlewares/setup.py

@@ -160,6 +160,7 @@ setup(
     extras_require={
         "dev": [
             "0x-contract-addresses",
+            "0x-contract-wrappers",
             "0x-order-utils",
             "web3",
             "bandit",