bpo-29919: Remove unused imports found by pyflakes (#137)

Make also minor PEP8 coding style fixes on modified imports.

Tools/clinic/clinic.py

@@ -7,7 +7,6 @@
 
 import abc
 import ast
-import atexit
 import collections
 import contextlib
 import copy
@@ -27,7 +26,6 @@ import tempfile
 import textwrap
 import traceback
 import types
-import uuid
 
 from types import *
 NoneType = type(None)

Tools/msi/make_zip.py

@@ -10,7 +10,7 @@ import tempfile
 from itertools import chain
 from pathlib import Path
 from zipfile import ZipFile, ZIP_DEFLATED
-import subprocess
+
 
 TKTCL_RE = re.compile(r'^(_?tk|tcl).+\.(pyd|dll)', re.IGNORECASE)
 DEBUG_RE = re.compile(r'_d\.(pyd|dll|exe|pdb|lib)$', re.IGNORECASE)

Tools/tz/zdump.py

@@ -3,7 +3,7 @@ import os
 import struct
 from array import array
 from collections import namedtuple
-from datetime import datetime, timedelta
+from datetime import datetime
 
 ttinfo = namedtuple('ttinfo', ['tt_gmtoff', 'tt_isdst', 'tt_abbrind'])