Add missing --add-host args to the build command

Signed-off-by: José Rodrigues <contact.jrodrigues@gmail.com>

compose/service.py

@@ -1875,6 +1875,11 @@ class _CLIBuilder:
         command_builder.add_arg("--iidfile", iidfile)
         command_builder.add_arg("--platform", platform)
         command_builder.add_arg("--isolation", isolation)
+
+        if extra_hosts:
+            for host, ip in extra_hosts.items():
+                command_builder.add_arg("--add-host", "{}:{}".format(host, ip))
+
         args = command_builder.build([path])
 
         magic_word = "Successfully built "