Add AMQP transport (go-kit#746) (go-kit#746) amqp transport publisher amqp transport tests lint fixes for amqp transport fixed formatting and punctuation zzz default ContentType is null, increased max length of correlationId to 255 refractored subscriber EncodeResponseFunc into encode func, and send func zzz

rm ROADMAP.md 

Merge pull request go-kit#619 from karthikmuralidharan/patch-1 fix typo in addcli

Merge pull request go-kit#550 from yurishkuro/ys-fix-549 Simplify and fix unstable test

log/level: remove outdated comment 

Release 0.3.0 

Merge pull request go-kit#330 from basvanbeek/master follow opentracing-go refactoring of HTTPHeadersCarrier

Merge pull request go-kit#287 from go-kit/addsvc-errors examples/addsvc: more sophisticated error encoding