Reformat imports with isort (#3123)

Besides that:
1. Introduce `setup.py isort` for quick check
2. Introduce GH actions to check imports

features/archive-restore.py

@@ -1,6 +1,6 @@
 #!/usr/bin/env python
-import os
 import argparse
+import os
 import shutil
 
 if __name__ == "__main__":

features/callback2.py

@@ -1,5 +1,6 @@
 #!/usr/bin/env python
 
 import sys
+
 with open("data/{0}/{0}_cb.log".format(sys.argv[1]), "a+") as log:
     log.write(" ".join(sys.argv[-3:]) + "\n")

features/environment.py

@@ -1,9 +1,8 @@
 import abc
 import datetime
 import glob
-import os
 import json
-import psutil
+import os
 import re
 import shutil
 import signal
@@ -13,11 +12,14 @@ import sys
 import tempfile
 import threading
 import time
+
+from http.server import BaseHTTPRequestHandler, HTTPServer
+
+import psutil
 import yaml
 
 import patroni.psycopg as psycopg
 
-from http.server import BaseHTTPRequestHandler, HTTPServer
 from patroni.request import PatroniRequest
 
 
@@ -498,6 +500,7 @@ class AbstractEtcdController(AbstractDcsController):
 
     def _is_running(self):
         from patroni.dcs.etcd import DnsCachingResolver
+
         # if etcd is running, but we didn't start it
         try:
             self._client = self._client_cls({'host': 'localhost', 'port': 2379, 'retry_timeout': 30,

features/steps/basic_replication.py

@@ -1,8 +1,10 @@
 import json
-import patroni.psycopg as pg
+
+from time import sleep, time
 
 from behave import step, then
-from time import sleep, time
+
+import patroni.psycopg as pg
 
 
 @step('I start {name:w}')

features/steps/citus.py

@@ -1,11 +1,12 @@
 import json
 import time
 
-from behave import step, then
-from dateutil import tz
 from datetime import datetime
 from functools import partial
-from threading import Thread, Event
+from threading import Event, Thread
+
+from behave import step, then
+from dateutil import tz
 
 tzutc = tz.tzutc()
 

features/steps/patroni_api.py

@@ -1,14 +1,16 @@
 import json
-import parse
 import shlex
 import subprocess
 import sys
 import time
+
+from datetime import datetime, timedelta
+
+import parse
 import yaml
 
 from behave import register_type, step, then
 from dateutil import tz
-from datetime import datetime, timedelta
 
 tzutc = tz.tzutc()
 

features/steps/slots.py

@@ -2,6 +2,7 @@ import json
 import time
 
 from behave import step, then
+
 import patroni.psycopg as pg
 
 

features/steps/watchdog.py

@@ -1,6 +1,7 @@
-from behave import step, then
 import time
 
+from behave import step, then
+
 
 def polling_loop(timeout, interval=1):
     """Returns an iterator that returns values until timeout has passed. Timeout is measured from start of iteration."""