fix: simplify workingDirectory

Author: aminya

lib/grammar-utils.js

@@ -73,12 +73,9 @@ const GrammarUtils = {
 
   /** get workingDirectory */
   workingDirectory() {
-    const activePane = atom.workspace.getActivePaneItem()
-    if (activePane && activePane.buffer && activePane.buffer.file && activePane.buffer.file.getParent) {
-      const parent = activePane.buffer.file.getParent()
-      if (parent && parent.getPath) {
-        return parent.getPath()
-      }
+    const textEditor = atom.workspace.getActiveTextEditor()
+    if (textEditor !== undefined) {
+      return textEditor.getDirectoryPath()
     }
     return process.cwd()
   },