- Update to version 6.2.4
* Deleted more obsolete items.
- Update to version 6.2.3
* Removed unused dependencies.
- Enable tests
- Get source from pypi, github tag doesn't have the latest version and
looks like the releases are not done in the github.

- Update to version 6.2.2
* Cleaned up sync API leftover.
* Retired temporary sync API.
* Removed package postfix. A helper release to enable migration.
* Merged changes from 4.4.13.
* Fixed more access descriptors.
* Initial work to support pysmi-lextudio 1.3.0 and above.
* Removed package postfix. A helper release to enable migration.
* Restricted pysmi-lextudio version to 1.2.0 to avoid
breaking changes.
* Fixed walkCmd bug.
* Fixed bulkWalkCmd bug.
* Added sync oneliner back.
* Fix annotations.
* Added walkCmd() and bulkWalkCmd() to hlapi.
* Improved Slim class to support IPv6.
* Added some sync API based on asyncio.
* Added custom socket support in openServerMode.
* Fixed various bugs in RFC3414 error handling.
* Reverted some changes in 6.0.2 on asyncio dispatch.
* Deleted asyncore related bits.
* Simplified asyncio dispatch.