Migrate Python libraries to v3 (#2284)

* .gitignore migrations/0x_ganache_snapshot

* .gitignore new-ish Python contract wrappers

These should have been added back when we started generating these
wrappers.

* rm superfluous contract artifact in Python package

All of the contract artifacts were removed from the Python package
recently, because now they're copied from the monorepo/packages area as
an automated build step.  Somehow this one artifact slipped through the
cracks.

* Eliminate circular dependency

This was preventing the Exchange wrapper from ever importing its
validator!

* Improve output of monorepo-level parallel script

- Capture stderr (and have it included in stdout) so that it doesn't
leak onto the console for commands that didn't actually fail.

- Include all error output in the Exception object (eliminate print
statement).

* Silence new versions of linters

Newer versions care about this stuff.  Old versions didn't, and we don't
either.

* Support Rich Reverts via Web3.py middleware

* Fix bug in generated wrappers' bytes handling

`bytes.fromhex(bytes.decode('utf-8')` is just plain wrong.  It would
work for some cases, but is not working when trying to fill orders with
the latest Exchange contract.

* Migrate to Exchange v3

* Fix typo in DevUtils documentation

* Include new contracts in docs

* Re-enable Python checks in CI

* Accept strings for bytes

* Fix CircleCI build artifacts for gen'd python

I swear the previous way was working before, but it wasn't working now,
so this fixes it.

* Accept a provider OR a Web3 object

In various places.  This allows the caller to install middleware (which
in web3.py is installed on a Web3 object, not on a provider) before
executing any RPC calls, which is important for the case where one wants
to produce signatures locally before submitting to a remote node.

* wrapper base: don't assume there are accounts

* Eliminate some inline linter directives

* make CHANGELOGs be REVERSE chronological

* Update CHANGELOG entries and bump version numbers

* @0x/contract-addresses: Put addr's in JSON, not TS

This allows easier consumption by other languages.  (Specifically, it
eliminates the overhead of keeping the Python addresses package in sync
with the TypeScript one.)

* sra_client.py: incl. docker in `./setup.py clean`

* sra_client.py: Migrate to protocol v3

Removed script that existed only to exclude runs of sra_client builds
(parallel_without_sra_client).  Now `parallel` is used by CI,
re-including sra_client in CI checks.

* abi-gen/templates/Py: clarify if/else logic

In response to
https://github.com/0xProject/0x-monorepo/pull/2284#discussion_r342200906

* sra_client.py: Update CHANGELOG and bump version

* contract_addresses/setup.py: rm unnecessary rm

* json_schemas.py: corrections to dev dependencies

* In tests against deployment, also run doctests

* contract_wrappers example: rm xtra Order attribute

Thanks to @steveklebanoff for catching this.
https://github.com/0xProject/0x-monorepo/pull/2284#pullrequestreview-312065368

python-packages/order_utils/test/test_generate_order_hash_hex.py

@@ -6,7 +6,7 @@ from zero_ex.order_utils import generate_order_hash_hex
 def test_get_order_hash_hex__empty_order():
     """Test the hashing of an uninitialized order."""
     expected_hash_hex = (
-        "faa49b35faeb9197e9c3ba7a52075e6dad19739549f153b77dfcf59408a4b422"
+        "331cb7e07a757bae130702da6646c26531798c92bcfaf671817268fd2c188531"
     )
     actual_hash_hex = generate_order_hash_hex(
         {
@@ -18,6 +18,8 @@ def test_get_order_hash_hex__empty_order():
             ),
             "makerAssetData": (b"\x00") * 20,
             "takerAssetData": (b"\x00") * 20,
+            "makerFeeAssetData": (b"\x00") * 20,
+            "takerFeeAssetData": (b"\x00") * 20,
             "salt": 0,
             "makerFee": 0,
             "takerFee": 0,
@@ -25,6 +27,7 @@ def test_get_order_hash_hex__empty_order():
             "takerAssetAmount": 0,
             "expirationTimeSeconds": 0,
         },
-        "0x0000000000000000000000000000000000000000",
+        "0x1dc4c1cefef38a777b15aa20260a54e584b16c48",
+        50,
     )
     assert actual_hash_hex == expected_hash_hex

python-packages/order_utils/test/test_signature_utils.py

@@ -3,6 +3,10 @@
 import pytest
 from web3 import Web3
 
+from zero_ex.contract_wrappers.exchange.exceptions import (
+    SignatureError,
+    SignatureErrorCodes,
+)
 from zero_ex.order_utils import is_valid_signature, sign_hash_to_bytes
 
 
@@ -117,28 +121,49 @@ def test_is_valid_signature__unsupported_sig_types():
 
     To induce this error, the last byte of the signature is tweaked from 03 to
     ff."""
-    (is_valid, reason) = is_valid_signature(
-        Web3.HTTPProvider("http://127.0.0.1:8545"),
-        "0x6927e990021d23b1eb7b8789f6a6feaf98fe104bb0cf8259421b79f9a34222b0",
-        "0x1B61a3ed31b43c8780e905a260a35faefcc527be7516aa11c0256729b5b351bc334"
-        + "0349190569279751135161d22529dc25add4f6069af05be04cacbda2ace2254ff",
-        "0x5409ed021d9299bf6814279a6a1411a7e866a631",
-    )
-    assert is_valid is False
-    assert reason == "SIGNATURE_UNSUPPORTED"
+    try:
+        is_valid_signature(
+            Web3.HTTPProvider("http://127.0.0.1:8545"),
+            "0x6927e990021d23b1eb7b8789f6a6feaf98fe104bb0cf8259421b79f9a34222"
+            + "b0",
+            "0x1B61a3ed31b43c8780e905a260a35faefcc527be7516aa11c0256729b5b351b"
+            + "c3340349190569279751135161d22529dc25add4f6069af05be04cacbda2ace"
+            + "225401",
+            "0x5409ed021d9299bf6814279a6a1411a7e866a631",
+        )
+    except SignatureError as signature_error:
+        assert (
+            signature_error.errorCode
+            == SignatureErrorCodes.INVALID_LENGTH.value
+        )
+    else:
+        pytest.fail("Expected exception")
 
 
-def test_sign_hash_to_bytes__golden_path():
+def test_sign_hash_to_bytes_and_validate__golden_path():
     """Test the happy path through sign_hash_to_bytes()."""
     provider = Web3.HTTPProvider("http://127.0.0.1:8545")
-    signature = sign_hash_to_bytes(
-        provider,
-        Web3(  # pylint: disable=no-member
-            provider
-        ).geth.personal.listAccounts()[0],
-        "0x34decbedc118904df65f379a175bb39ca18209d6ce41d5ed549d54e6e0a95004",
+
+    signing_address = Web3(  # pylint: disable=no-member
+        provider
+    ).geth.personal.listAccounts()[0]
+
+    order_hash_hex = (
+        "0x34decbedc118904df65f379a175bb39ca18209d6ce41d5ed549d54e6e0a95004"
     )
+
+    signature = sign_hash_to_bytes(provider, signing_address, order_hash_hex)
+
     assert (
         signature
         == b"1b117902c86dfb95fe0d1badd983ee166ad259b27acb220174cbb4460d872871137feabdfe76e05924b484789f79af4ee7fa29ec006cedce1bbf369320d034e10b03"  # noqa: E501 (line too long)
     )
+
+    is_valid = is_valid_signature(
+        Web3.HTTPProvider("http://127.0.0.1:8545"),
+        order_hash_hex,
+        signature.decode("utf-8"),
+        signing_address,
+    )
+
+    assert is_valid is True