2e: releasetools: Address PEP8 warnings

- Dropped unused 're' import
- Addred required blank lines
- Fixed indentation

References:
[0]: https://www.python.org/dev/peps/pep-0008/#blank-lines
[1]: https://www.python.org/dev/peps/pep-0008/#indentation



Signed-off-by: Aayush Gupta <aayushgupta219@gmail.com>
Change-Id: I0316386ffee860a9859968df1cea30d049adf68c