Refactor integration tests of compression codecs

Motivation:

Duplicated code of integration tests for different compression codecs.

Modifications:

- Added abstract class `IntegrationTest` which contains common tests for any compression codec.
- Removed common tests from `Bzip2IntegrationTest` and `LzfIntegrationTest`.
- Implemented abstract methods of `IntegrationTest` in `Bzip2IntegrationTest`, `LzfIntegrationTest` and `SnappyIntegrationTest`.

Result:

Removed duplicated code of integration tests for compression codecs and simplified an addition of integration tests for new compression codecs.