v0.10.0: Fix prometheus test (#49)
- use common/expfmt instead of local http fetch for PushGateway #29
- change summary to histogram #35
- Allow dump request/response body to opentracing's tags #38
- chore: upgrade prometheus to v1.5.1 #40
- adding pprof middleware #42
- feat(casbin): let the caller decide the method of user identification #41
- adding zipkin open tracing #48
- fixing prometheus test #49