Bump character configuration to v8 and add migration script.

nucypher/config/base.py

@@ -303,7 +303,7 @@ class CharacterConfiguration(BaseConfiguration):
     'Sideways Engagement' of Character classes; a reflection of input parameters.
     """
 
-    VERSION = 7  # bump when static payload scheme changes
+    VERSION = 8  # bump when static payload scheme changes
 
     CHARACTER_CLASS = NotImplemented
     MNEMONIC_KEYSTORE = False

nucypher/config/migrations/__init__.py

@@ -5,6 +5,7 @@ from .configuration_v3_to_v4 import configuration_v3_to_v4
 from .configuration_v4_to_v5 import configuration_v4_to_v5
 from .configuration_v5_to_v6 import configuration_v5_to_v6
 from .configuration_v6_to_v7 import configuration_v6_to_v7
+from .configuration_v7_to_v8 import configuration_v7_to_v8
 
 MIGRATIONS = OrderedDict(
     {
@@ -14,5 +15,6 @@ MIGRATIONS = OrderedDict(
         (4, 5): configuration_v4_to_v5,
         (5, 6): configuration_v5_to_v6,
         (6, 7): configuration_v6_to_v7,
+        (7, 8): configuration_v7_to_v8,
     }
 )

nucypher/config/migrations/configuration_v7_to_v8.py

@@ -0,0 +1,24 @@
+from typing import Dict
+
+from nucypher.config.migrations.common import perform_migration
+
+
+def __migration(config: Dict) -> Dict:
+    # deprecations
+    del config["pre_payment_network"]
+
+    # eth_provider_uri -> eth_endpoint
+    config["eth_endpoint"] = config["eth_provider_uri"]
+    del config["eth_provider_uri"]
+
+    # pre_payment_provider -> polygon_endpoint
+    config["polygon_endpoint"] = config["pre_payment_provider"]
+    del config["pre_payment_provider"]
+
+    return config
+
+
+def configuration_v7_to_v8(filepath) -> None:
+    perform_migration(
+        old_version=7, new_version=8, migration=__migration, filepath=filepath
+    )