swap to sys exit

manage branches.py

@@ -92,13 +92,13 @@ while True:
           Either set the environment variable to a 'WRITE' token or remove it.
                   ''')
             input("Press enter to continue.")
-            exit()
+            sys.exit("Exiting...")
         if os.environ.get('COLAB_BACKEND_VERSION', None) is not None:
             print('''
                               Your Colab secret key is read-only
                 Please switch your key to 'write' or disable notebook access on the left.
-                               For now, you are stuck in a loop
                   ''')
+            sys.exit("Stuck in a loop, exiting...")
         elif os.environ.get('KAGGLE_KERNEL_RUN_TYPE', None) is not None:
             print('''
                                       Your Kaggle secret key is read-only
@@ -156,7 +156,7 @@ if yorn == 'y':
         delete_branch(repo, repo_type=r_type, branch=branch)
 else:
     print("Cancelled action")
-    exit()
+    sys.exit("Exiting...")
 clear_screen()
 
 #extra information for the user