load-language as given to odoo for language installation on a database

docker_dev_start.py

@@ -234,6 +234,13 @@
         action='store_false',
         dest='dev',
     )
+    parser.add_argument(
+        '--load-language',
+        help="specifies the languages for the translations you want to be"
+             " loaded",
+        default=None,
+        dest='LOAD_LANGUAGE',
+    )
     # TODO there are more
     odoo_log_levels = ['info', 'warn', 'debug', 'debug_sql']
     parser.add_argument(
@@ -373,6 +380,9 @@
     if nmspc.log_level:
         arg.append('--log-level')
         arg.append(nmspc.log_level)
+    if nmspc.LOAD_LANGUAGE:
+        arg.append('--load-language')
+        arg.append(nmspc.LOAD_LANGUAGE)
 
     # auto detect local ip
     if use_host_network: