Tweaks to file_server initialisation

We are setting a sensible default for the storage folder and loading
that automatically, this way we avoid having a compulsory config file.

attract/config.py.example

@@ -1,6 +1,5 @@
 import os
 
-
 class Config(object):
     # Configured for GMAIL
     MAIL_SERVER = ''
@@ -20,19 +19,10 @@ class Config(object):
     SECURITY_PASSWORD_SALT = ''
     SECURITY_EMAIL_SENDER = ''
 
-
 class Development(Config):
     SECRET_KEY = ''
-    #SERVER_NAME = 'attract.local:5555'
     HOST = '0.0.0.0'
     PORT = 5000
     DEBUG = True
-    SQLALCHEMY_DATABASE_URI = ''
-    SECURITY_REGISTERABLE = True
-    SECURITY_LOGIN_USER_TEMPLATE = 'security/login_user.html'
-    MEDIA_FOLDER = ''
-    MEDIA_URL = ''
-    MEDIA_THUMBNAIL_FOLDER = ''
-    MEDIA_THUMBNAIL_URL = ''
     FILE_STORAGE = '{0}/application/static/storage'.format(
         os.path.join(os.path.dirname(__file__)))