Bump to v0.4.3 (tikv#231)

* raft: leader respond to learner read index message (tikv#220)

Signed-off-by: nolouch <[email protected]>

* Bump to v0.4.3

Signed-off-by: Neil Shen <[email protected]>

0.4.2

0.4.1

0.5.0 (tikv#182)

Signed-off-by: Ana Hobden <[email protected]>

Release 0.4.0 (tikv#123)

v0.3.1 (tikv#92)

Use the old way to read enum (tikv#75)

version 0.2.0

- Deprecated sync-log and add context
- Fix learner isolation bug
- Port several tests
- Add examples
- Use fxhash

Initial release