Fix code lenses getting stuck when file is renamed

This caused the editor to get a new "long title", thus causing the 
previous lenses to never be cleaned up.

References #460

lib/CodeLensManager.js

@@ -90,13 +90,11 @@ class CodeLensManager
     registerMarker(editor, range, options) {
         const marker = editor.markBufferRange(range, options);
 
-        const longTitle = editor.getLongTitle();
-
-        if (!(longTitle in this.markers)) {
-            this.markers[longTitle] = [];
+        if (!(editor.id in this.markers)) {
+            this.markers[editor.id] = [];
         }
 
-        this.markers[longTitle].push(marker);
+        this.markers[editor.id].push(marker);
 
         return marker;
     }
@@ -105,13 +103,11 @@ class CodeLensManager
      * @param {TextEditor} editor
      */
     removeMarkers(editor) {
-        const longTitle = editor.getLongTitle();
-
-        for (let i in this.markers[longTitle]) {
-            const marker = this.markers[longTitle][i];
+        for (let i in this.markers[editor.id]) {
+            const marker = this.markers[editor.id][i];
             marker.destroy();
         }
 
-        this.markers[longTitle] = [];
+        this.markers[editor.id] = [];
     }
 };