[gnome-builder] cargo: add display name getter

[Christian Hergert <chergert src gnome org>]

commit 227fa7743085d0549767ae4c1a38c449a32c2782
Author: Christian Hergert <chergert redhat com>
Date:   Mon Jan 21 10:32:35 2019 -0800

    cargo: add display name getter

 src/plugins/cargo/cargo_plugin.py | 3 +++
 1 file changed, 3 insertions(+)
---
diff --git a/src/plugins/cargo/cargo_plugin.py b/src/plugins/cargo/cargo_plugin.py
index 7fc7b14b4..815e017f8 100644
--- a/src/plugins/cargo/cargo_plugin.py
+++ b/src/plugins/cargo/cargo_plugin.py
@@ -162,6 +162,9 @@ class CargoBuildTarget(Ide.Object, Ide.BuildTarget):
     def do_get_install_directory(self):
         return None
 
+    def do_get_display_name(self):
+        return 'cargo run'
+
     def do_get_name(self):
         return 'cargo-run'