Merge pull request #643 from twitter/release-0.5.0

Release twemproxy 0.5.0

Merge pull request #640 from twitter/release-0.5.0-RC1

Release twemproxy 0.5.0-RC1

version 0.4.1

Merge pull request #255 from idning/ping_quit

ping & quit supported

version 0.2.4

version 0.2.3

version 0.2.2

version 0.2.1

version 0.2.0