CA-145177: [UnitTest] unit tests for flock.py

Signed-off-by: Mate Lakat <mate.lakat@citrix.com>
CA-145177: Remove non-used tests

Signed-off-by: Mate Lakat <mate.lakat@citrix.com>
CA-145177: Remove non-used method

Signed-off-by: Mate Lakat <mate.lakat@citrix.com>
CA-145177: Fix PEP8 violations

Signed-off-by: Mate Lakat <mate.lakat@citrix.com>