Add new travis feature for logind

.travis.yml

@@ -36,6 +36,7 @@ env:
     - FEATURES="backend_udev"
     - FEATURES="backend_session"
     - FEATURES="backend_session_udev"
+    - FEATURES="backend_session_logind"
     - FEATURES="renderer_glium"
       # test default features
     - FEATURES="default"

src/backend/session/auto.rs

@@ -79,7 +79,8 @@ pub enum BoundAutoSession {
 pub struct AutoId(AutoIdInternal);
 #[derive(PartialEq, Eq)]
 enum AutoIdInternal {
-    #[cfg(feature = "backend_session_logind")] Logind(logind::Id),
+    #[cfg(feature = "backend_session_logind")]
+    Logind(logind::Id),
     Direct(direct::Id),
 }