Add warning when using SQLite as the database backend.

Signed-off-by: Roberto Rosario <roberto.rosario.gonzalez@gmail.com>

mayan/apps/common/utils.py

@@ -20,12 +20,16 @@ from common.compat import dict_type, dictionary_type
 import mayan
 
 from .exceptions import NotLatestVersion
-from .literals import MAYAN_PYPI_NAME, PYPI_URL
+from .literals import DJANGO_SQLITE_BACKEND, MAYAN_PYPI_NAME, PYPI_URL
 from .settings import setting_temporary_directory
 
 logger = logging.getLogger(__name__)
 
 
+def check_for_sqlite():
+    return settings.DATABASES['default']['ENGINE'] == DJANGO_SQLITE_BACKEND
+
+
 def check_version():
     pypi = xmlrpc_client.ServerProxy(PYPI_URL)
     versions = pypi.package_releases(MAYAN_PYPI_NAME)