Can you update ocagent to work with latest census-instrumentation/opencensus-proto?

[eclipseo]

Hi,

I'm trying to use ocagent with latest census-instrumentation/opencensus-proto (v0.3.0) but there is a slight api discrepency:

Testing    in: /builddir/build/BUILD/opencensus-go-exporter-ocagent-0.7.0/_build/src
         PATH: /builddir/build/BUILD/opencensus-go-exporter-ocagent-0.7.0/_build/bin:/builddir/.local/bin:/builddir/bin:/usr/bin:/bin:/usr/sbin:/sbin:/usr/local/sbin
       GOPATH: /builddir/build/BUILD/opencensus-go-exporter-ocagent-0.7.0/_build:/usr/share/gocode
  GO111MODULE: off
      command: go test -buildmode pie -compiler gc -ldflags " -X contrib.go.opencensus.io/exporter/ocagent/version=0.7.0 -extldflags '-Wl,-z,relro -Wl,--as-needed  -Wl,-z,now -specs=/usr/lib/rpm/redhat/redhat-hardened-ld '"
      testing: contrib.go.opencensus.io/exporter/ocagent
contrib.go.opencensus.io/exporter/ocagent
# contrib.go.opencensus.io/exporter/ocagent [contrib.go.opencensus.io/exporter/ocagent.test]
./viewdata_to_metrics_test.go:77:45: cannot use ma (type *metricsAgent) as type "github.com/census-instrumentation/opencensus-proto/gen-go/agent/metrics/v1".MetricsServiceServer in argument to "github.com/census-instrumentation/opencensus-proto/gen-go/agent/metrics/v1".RegisterMetricsServiceServer:
	*metricsAgent does not implement "github.com/census-instrumentation/opencensus-proto/gen-go/agent/metrics/v1".MetricsServiceServer (missing "github.com/census-instrumentation/opencensus-proto/gen-go/agent/metrics/v1".mustEmbedUnimplementedMetricsServiceServer method)
FAIL	contrib.go.opencensus.io/exporter/ocagent [build failed]

I tried to do it myself but I don't know enough Go to fix this. Could you patch it in master?

Thanks,

Robert-André