Use ValidationError from eth_utils

Having a ValidationError defined both here and there makes no sense
and forces callsites to catch them both in some situations.

eth_keys/datatypes.py

@@ -27,6 +27,8 @@
     keccak,
     to_checksum_address,
     to_normalized_address,
+    ValidationError,
+
 )
 
 from eth_keys.utils.address import (
@@ -41,7 +43,6 @@
 
 from eth_keys.exceptions import (
     BadSignature,
-    ValidationError,
 )
 from eth_keys.validation import (
     validate_private_key_bytes,

eth_keys/exceptions.py

@@ -1,6 +1,2 @@
-class ValidationError(Exception):
-    pass
-
-
 class BadSignature(Exception):
     pass

eth_keys/main.py

@@ -1,5 +1,10 @@
 from typing import (Any, Union, Type)  # noqa: F401
 
+from eth_utils import (
+    is_string,
+    ValidationError,
+)
+
 from eth_keys.datatypes import (
     BaseSignature,
     LazyBackend,
@@ -8,9 +13,6 @@
     PrivateKey,
     Signature,
 )
-from eth_keys.exceptions import (
-    ValidationError,
-)
 from eth_keys.validation import (
     validate_message_hash,
     validate_compressed_public_key_bytes,

eth_keys/validation.py

@@ -4,15 +4,13 @@
     encode_hex,
     is_bytes,
     is_integer,
+    ValidationError,
 )
 from eth_utils.toolz import curry
 
 from eth_keys.constants import (
     SECPK1_N,
 )
-from eth_keys.exceptions import (
-    ValidationError,
-)
 
 
 def validate_integer(value: Any) -> None:

tests/core/test_key_and_signature_datastructures.py

@@ -10,13 +10,11 @@
     is_normalized_address,
     is_checksum_address,
     is_canonical_address,
+    ValidationError,
 )
 
 from eth_keys import KeyAPI
 from eth_keys.backends import NativeECCBackend
-from eth_keys.exceptions import (
-    ValidationError,
-)
 
 
 MSG = b'message'

tests/core/test_key_api_proxy_methods.py

@@ -2,11 +2,11 @@
 
 from eth_utils import (
     keccak,
+    ValidationError,
 )
 
 from eth_keys import KeyAPI
 from eth_keys.backends import NativeECCBackend
-from eth_keys.exceptions import ValidationError
 
 
 MSG = b'message'