Update installation routine and docs

- Single call of "make install" does everything
- Add backup_dir option to yaml config file

InvenTree/InvenTree/settings.py

@@ -231,4 +231,6 @@ IMPORT_EXPORT_USE_TRANSACTIONS = True
 
 # Settings for dbbsettings app
 DBBACKUP_STORAGE = 'django.core.files.storage.FileSystemStorage'
-DBBACKUP_STORAGE_OPTIONS = {'location': tempfile.gettempdir()}
+DBBACKUP_STORAGE_OPTIONS = {
+    'location': CONFIG.get('backup_dir', tempfile.gettempdir()),
+}

InvenTree/config.yaml

@@ -43,4 +43,8 @@ media_root: './media'
 static_root: './static'
 
 # Logging options
-log_queries: False
+log_queries: False
+
+# Backup options
+# Set the backup_dir parameter to store backup files in a specific location
+# backup_dir = "/home/me/inventree-backup/"