Fix dependency issues when GO111MODULE is disabled. (#111)

* Use master for core library and ocagent exporter for now.

* Fix exemplar dependency.

* Also test GO111MODULE=off in travis.

* Use tagged version for ocagent exporter.

* Fix travis script.

Author: songy23

.travis.yml

@@ -18,4 +18,7 @@ script:
   - if [ -n "$(gofmt -s -l $GO_FILES)" ]; then echo "gofmt the following files:"; gofmt -s -l $GO_FILES; exit 1; fi
   - go vet ./...
   - go test -v -race $PKGS            # Run all the tests with the race detector enabled
+  - GO111MODULE=off go get -t ./...
+  - GO111MODULE=off go build ./...
+  - GO111MODULE=off go test -v -race $PKGS            # Make sure tests still pass when not using Go modules.
   - 'if [[ $TRAVIS_GO_VERSION = 1.8* ]]; then ! golint ./... | grep -vE "(_mock|_string|\.pb)\.go:"; fi'

equivalence_test.go

@@ -25,7 +25,7 @@ import (
 	"time"
 
 	"contrib.go.opencensus.io/exporter/ocagent"
-	"go.opencensus.io/exemplar"
+	"go.opencensus.io/metric/metricdata"
 	"go.opencensus.io/stats"
 	"go.opencensus.io/stats/view"
 	"google.golang.org/api/option"
@@ -193,7 +193,7 @@ func TestEquivalenceStatsVsMetricsUploads(t *testing.T) {
 							Max:            500,
 							Mean:           125.9,
 							CountPerBucket: []int64{0, 1, 0, 0, 0, 0, 0},
-							ExemplarsPerBucket: []*exemplar.Exemplar{
+							ExemplarsPerBucket: []*metricdata.Exemplar{
 								nil,
 								{
 									Value: 125.9, Timestamp: startTime.Add(time.Duration(1+i) * time.Second),

go.mod

@@ -2,16 +2,18 @@ module contrib.go.opencensus.io/exporter/stackdriver
 
 require (
 	cloud.google.com/go v0.36.0
-	contrib.go.opencensus.io/exporter/ocagent v0.4.7
+	contrib.go.opencensus.io/exporter/ocagent v0.4.8
 	contrib.go.opencensus.io/resource v0.0.0-20190131005048-21591786a5e0
 	github.com/aws/aws-sdk-go v1.17.5
 	github.com/census-instrumentation/opencensus-proto v0.2.0
 	github.com/golang/protobuf v1.3.0
 	github.com/google/go-cmp v0.2.0
-	go.opencensus.io v0.19.0
-	golang.org/x/net v0.0.0-20181217023233-e147a9138326
-	golang.org/x/oauth2 v0.0.0-20181203162652-d668ce993890
-	google.golang.org/api v0.1.0
-	google.golang.org/genproto v0.0.0-20190201180003-4b09977fb922
-	google.golang.org/grpc v1.18.0
+	github.com/grpc-ecosystem/grpc-gateway v1.8.5 // indirect
+	go.opencensus.io v0.19.2-0.20190319182201-ebb7978abd3f // TODO(songy23): use the released versoin once new release is publised.
+	golang.org/x/net v0.0.0-20190311183353-d8887717615a
+	golang.org/x/oauth2 v0.0.0-20190226205417-e64efc72b421
+	google.golang.org/api v0.2.0
+	google.golang.org/genproto v0.0.0-20190307195333-5fe7a883aa19
+	google.golang.org/grpc v1.19.0
+	gopkg.in/yaml.v2 v2.2.2 // indirect
 )