Update Zipkin API (#110)

## Which problem is this PR solving?
- Swagger Docker image is no longer value

## Description of the changes
- Upgrade swagger image version to 0.31
- That fails on the old API definition for Zipkin, so update that from
the latest

## How was this change tested?
- CI

---------

Signed-off-by: Yuri Shkuro <github@ysh.us>

Makefile

@@ -3,7 +3,7 @@ THRIFT_VER?=0.13
 THRIFT_IMG?=jaegertracing/thrift:$(THRIFT_VER)
 THRIFT=docker run --rm -u $(shell id -u) -v "${PWD}:/data" $(THRIFT_IMG) thrift
 
-SWAGGER_VER=0.12.0
+SWAGGER_VER=0.31.0
 SWAGGER_IMAGE=quay.io/goswagger/swagger:$(SWAGGER_VER)
 SWAGGER=docker run --rm -u ${shell id -u} -v "${PWD}:/go/src/${PROJECT_ROOT}" -w /go/src/${PROJECT_ROOT} $(SWAGGER_IMAGE)