Improve PEP8 compliance in etender_service.py

+from datetime import date, datetime, timedelta
+from dateutil.parser import parse
+from dateutil.tz import tzlocal
 from iso8601 import parse_date
+from jsonpath_rw import parse as parse_path
+from pytz import timezone
 from robot.output import LOGGER
 from robot.output.loggerhelper import Message
 from robot.libraries.BuiltIn import BuiltIn
 from robot.errors import HandlerExecutionFailed
-from datetime import datetime, timedelta, date
-from dateutil.parser import parse
-from dateutil.tz import tzlocal
-from pytz import timezone
-from jsonpath_rw import parse as parse_path
-import time
 from op_robot_tests.tests_files.initial_data import (
     test_tender_data
 )
+import time
 
 TIMEZONE = timezone('Europe/Kiev')
 
+
 def convert_date_to_etender_format(isodate):
-    iso_dt=parse_date(isodate)
+    iso_dt = parse_date(isodate)
     date_string = iso_dt.strftime("%d-%m-%Y")
-    return  date_string
+    return date_string
+
 
 def convert_time_to_etender_format(isodate):
-    iso_dt=parse_date(isodate)
+    iso_dt = parse_date(isodate)
     time_string = iso_dt.strftime("%H:%M")
-    return  time_string
+    return time_string