Fix code quality issues

river/admin/__init__.py

@@ -1,10 +1,8 @@
-from django.contrib import admin
-
 from river.admin.function_admin import *
-from river.admin.transitionmeta import *
+from river.admin.hook_admins import *
 from river.admin.transitionapprovalmeta import *
+from river.admin.transitionmeta import *
 from river.admin.workflow import *
-from river.admin.hook_admins import *
 from river.models import State
 
 admin.site.register(State)

river/core/instanceworkflowobject.py

@@ -3,7 +3,7 @@
 import six
 from django.contrib.contenttypes.models import ContentType
 from django.db import transaction
-from django.db.models import Q, Max, F
+from django.db.models import Q, Max
 from django.db.transaction import atomic
 from django.utils import timezone
 

river/migrations/0010_auto_20191110_1045.py

@@ -4,9 +4,8 @@
 
 from uuid import uuid4
 
-from django.db import migrations, models
 import django.db.models.deletion
-from django.db.models import F
+from django.db import migrations, models
 
 from river.models import CANCELLED, APPROVED
 from river.models.transition import DONE

river/models/transitionapprovalmeta.py

@@ -1,12 +1,12 @@
 from __future__ import unicode_literals
 
 from django.db import models, transaction
-from django.db.models import CASCADE, PROTECT
+from django.db.models import PROTECT
 from django.db.models.signals import post_save, pre_delete
 from django.utils.translation import ugettext_lazy as _
 
 from river.config import app_config
-from river.models import Workflow, State
+from river.models import Workflow
 from river.models.base_model import BaseModel
 from river.models.managers.transitionmetada import TransitionApprovalMetadataManager
 from river.models.transitionmeta import TransitionMeta

river/tests/hooking/test__approved_hooking.py

@@ -1,5 +1,5 @@
 from django.contrib.contenttypes.models import ContentType
-from hamcrest import equal_to, assert_that, none, has_entry, all_of, has_key, has_length, is_, is_not, has_item
+from hamcrest import equal_to, assert_that, none, has_entry, all_of, has_key, has_length, is_not
 
 from river.models import TransitionApproval
 from river.models.factories import PermissionObjectFactory, UserObjectFactory, StateObjectFactory, WorkflowFactory, TransitionApprovalMetaFactory, TransitionMetaFactory

river/tests/matchers.py

@@ -1,4 +1,4 @@
-from hamcrest import all_of, has_property, any_of
+from hamcrest import all_of, has_property
 from hamcrest.core.base_matcher import BaseMatcher
 from hamcrest.core.helpers.wrap_matcher import wrap_matcher