fix: prevent FileNotFoundError when storages.touch() is called with a…

[n1teshy]

Hi, the touch function in storages.py calls os.makedirs if create_dirs is True, but a user may unknowingly pass create_dirs as True even when the JSON file to be created is in the current working directory, in which case, the file's directory would be an empty string and FileNotFoundError would be raised by os.makedirs.

from tinydb import TinyDB

TinyDB("some.json", create_dirs=True)

Traceback (most recent call last):
File "", line 1, in
TinyDB('some.json', create_dirs=True)
~~~~~~^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
File "/home/nitesh/Desktop/programming/open-source/tinydb/tinydb/database.py", line 95, in init
self._storage: Storage = storage(*args, **kwargs)
~~~~~~~^^^^^^^^^^^^^^^^^
File "/home/nitesh/Desktop/programming/open-source/tinydb/tinydb/storages.py", line 117, in init
touch(path, create_dirs=create_dirs)
~~~~~^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
File "/home/nitesh/Desktop/programming/open-source/tinydb/tinydb/storages.py", line 28, in touch
os.makedirs(base_dir)
~~~~~~~~~~~^^^^^^^^^^
File "", line 236, in makedirs
FileNotFoundError: [Errno 2] No such file or directory: ''