Remove unused imports in the Python files

Found using flake8

python/mach/mach/commands/settings.py

@@ -6,10 +6,7 @@ from __future__ import print_function, unicode_literals
 
 from textwrap import TextWrapper
 
-from mach.decorators import (
-    CommandProvider,
-    Command,
-)
+from mach.decorators import Command
 
 
 #@CommandProvider

python/mach/mach/main.py

@@ -16,7 +16,6 @@ import os
 import sys
 import traceback
 import uuid
-import sys
 
 from .base import (
     CommandContext,
@@ -26,11 +25,7 @@ from .base import (
     UnrecognizedArgumentError,
 )
 
-from .decorators import (
-    CommandArgument,
-    CommandProvider,
-    Command,
-)
+from .decorators import CommandProvider
 
 from .config import ConfigSettings
 from .dispatcher import CommandAction

python/mach/mach/test/common.py

@@ -9,7 +9,6 @@ import os
 import unittest
 
 from mach.main import Mach
-from mach.base import CommandContext
 
 here = os.path.abspath(os.path.dirname(__file__))
 

python/mach/mach/test/providers/throw.py

@@ -4,8 +4,6 @@
 
 from __future__ import unicode_literals
 
-import time
-
 from mach.decorators import (
     CommandArgument,
     CommandProvider,

python/mach/mach/test/test_entry_point.py

@@ -11,8 +11,6 @@ from mach.base import MachError
 from mach.test.common import TestBase
 from mock import patch
 
-from mozunit import main
-
 
 here = os.path.abspath(os.path.dirname(__file__))