title: django makemigrations with python-social-auth leads to permission denied error
body: <p>After adding python social auth to my installed apps, i.e.</p>
  
  <pre><code>INSTALLED_APPS = (
      ...
      'social.apps.django_app.default',
      ...
  )
  </code></pre>
  
  <p>and then trying a </p>
  
  <pre><code>python manage.py makemigrations
  </code></pre>
  
  <p>I get an unsurprising permissions error</p>
  
  <pre><code>Migrations for 'default':
    0002_auto_20150217_2053.py:
      - Alter field user on usersocialauth
  Traceback (most recent call last):
    File "manage.py", line 10, in &lt;module&gt;
      execute_from_command_line(sys.argv)
    File "/usr/lib/python2.7/site-packages/django/core/management  /__init__.py", line 385, in execute_from_command_line
  utility.execute()
  File "/usr/lib/python2.7/site-packages/django/core/management/__init__.py", line 377, in execute
    self.fetch_command(subcommand).run_from_argv(self.argv)
  File "/usr/lib/python2.7/site-packages/django/core/management/base.py", line 288, in run_from_argv
    self.execute(*args, **options.__dict__)
  File "/usr/lib/python2.7/site-packages/django/core/management/base.py", line 338, in execute
    output = self.handle(*args, **options)
  File "/usr/lib/python2.7/site-packages/django/core/management/commands/makemigrations.py", line 124, in handle
    self.write_migration_files(changes)
  File "/usr/lib/python2.7/site-packages/django/core/management/commands /makemigrations.py", line 153, in write_migration_files
    with open(writer.path, "wb") as fh:
    IOError: [Errno 13] Permission denied: u'/usr/lib/python2.7/site-packages/social/apps/django_app/default/migrations/0002_auto_20150217_2053.py'
  </code></pre>
  
  <p>It makes sense that I can not write to system wide package installation directories. </p>
  
  <p>There are some obvious ways around this, like changing the permissions on the <em>site-packages/social</em> directories. However, is this the only way of doing this, or am I missing something?</p>