Update install_dependencies.sh

Error Found:
```
root@server:/data/crits# python manage.py create_default_collections
Traceback (most recent call last):
  File "manage.py", line 10, in <module>
    execute_from_command_line(sys.argv)
  File "/usr/local/lib/python2.7/dist-packages/django/core/management/__init__.py", line 399, in execute_from_command_line
    utility.execute()
  File "/usr/local/lib/python2.7/dist-packages/django/core/management/__init__.py", line 392, in execute
    self.fetch_command(subcommand).run_from_argv(self.argv)
  File "/usr/local/lib/python2.7/dist-packages/django/core/management/__init__.py", line 272, in fetch_command
    klass = load_command_class(app_name, subcommand)
  File "/usr/local/lib/python2.7/dist-packages/django/core/management/__init__.py", line 75, in load_command_class
    module = import_module('%s.management.commands.%s' % (app_name, name))
  File "/usr/local/lib/python2.7/dist-packages/django/utils/importlib.py", line 40, in import_module
    __import__(name)
  File "/data/crits/crits/core/management/commands/create_default_collections.py", line 7, in <module>
    from create_indexes import create_indexes
  File "/data/crits/crits/core/management/commands/create_indexes.py", line 7, in <module>
    from crits.core.mongo_tools import mongo_connector
  File "/data/crits/crits/core/mongo_tools.py", line 8, in <module>
    import magic
ImportError: No module named magic
```