some flake8 fixes

xonsh/completers/_aliases.py

@@ -120,8 +120,7 @@ def completer_alias(args, stdin=None):
         func = _list_completers
     return func(args[1:], stdin=stdin)
 
-COMPLETER_LIST_HELP_STR = \
-"""completer list: list the active completers, in order
+COMPLETER_LIST_HELP_STR = """completer list: ordered list the active completers
 
 Usage:
     completer remove

xonsh/completers/path.py

@@ -1,5 +1,4 @@
 import os
-import re
 import ast
 import builtins
 

xonsh/main.py

@@ -256,4 +256,3 @@ def main_context(argv=None):
     args = premain(argv)
     yield builtins.__xonsh_shell__
     postmain(args)
-

xonsh/platform.py

@@ -247,6 +247,7 @@ def windows_bash_command():
 # Environment variables defaults
 #
 
+
 @functools.lru_cache(1)
 def bash_command():
     """Determines the command for Bash on the current plaform."""