fix linting errors

src/fix_old_settings_file.py

@@ -1,7 +1,7 @@
 import sublime
-import sublime_plugin
 import os
 
+
 def plugin_loaded():
     t = sublime.load_settings('Project Manager.sublime-settings')
     s = sublime.load_settings('project_manager.sublime-settings')

src/json_file.py

@@ -1,6 +1,7 @@
 import sublime
 import os
 
+
 class JsonFile:
     def __init__(self, fpath, encoding='utf-8'):
         self.encoding = encoding

src/project_manager.py

@@ -1,5 +1,4 @@
 import sublime
-import sublime_plugin
 import subprocess
 import os
 import platform

src/window_commands.py

@@ -2,6 +2,7 @@ import sublime
 import sublime_plugin
 from .project_manager import Manager
 
+
 def cancellable(func):
     def _ret(self, action):
         if action >= 0: