Fix enum schema (#715)

* fix schema with enum fields - issue #699

* fix drivers dependencies - make them optional

* fix command

* provide extras

* add bolean field to related model

* add test with select related and boolean

* new test case based on issue

* fix bool issue in postgres limit queries - issue #704

* fix coverage

* bump version and add release info

tests/test_fastapi/test_enum_schema.py

@@ -0,0 +1,33 @@
+from enum import Enum
+
+import databases
+import sqlalchemy
+
+import ormar
+from tests.settings import DATABASE_URL
+
+database = databases.Database(DATABASE_URL, force_rollback=True)
+metadata = sqlalchemy.MetaData()
+
+
+class MyEnum(Enum):
+    SMALL = 1
+    BIG = 2
+
+
+class EnumExample(ormar.Model):
+    class Meta:
+        tablename = "enum_example"
+        metadata = metadata
+        database = database
+
+    id: int = ormar.Integer(primary_key=True)
+    size: MyEnum = ormar.Enum(enum_class=MyEnum, default=MyEnum.SMALL)
+
+
+def test_proper_schema():
+    schema = EnumExample.schema_json()
+    assert (
+        '{"MyEnum": {"title": "MyEnum", "description": "An enumeration.", '
+        '"enum": [1, 2]}}' in schema
+    )