Update app.py

Use `aclpubcheck` directly as installed from the package

app.py

@@ -56,7 +56,7 @@ def upload_file(file, paper_type):
     file_name_cmd = file.name.replace(" ", "\ ")
     file_name = get_filename(file.name)
     clear_cached_images(file_name)
-    command = f"python3 aclpubcheck-main/aclpubcheck/formatchecker.py --paper_type {paper_type} {file_name_cmd}"
+    command = f"aclpubcheck --paper_type {paper_type} {file_name_cmd}"
     out = subprocess.run(command, shell=True, stdout=subprocess.PIPE, text=True, stderr=subprocess.STDOUT)
     return to_html(remove_color_codes(out.stdout)) + add_images(file_name)