Upgrade to OpenTracing Go 1.2 (#525)

* Resolves #524
* Upgrades opentracing-go dependency to 1.2 (https://github.com/opentracing/opentracing-go/releases/tag/v1.2.0)
* Pin some Prometheus client libs in glide.yaml because some of their dependencies moved to go modules with v2, which is not supported by glide.

Signed-off-by: Yuri Shkuro <ys@uber.com>

Gopkg.toml

@@ -4,7 +4,7 @@
 
 [[constraint]]
   name = "github.com/opentracing/opentracing-go"
-  version = "^1.1"
+  version = "^1.2"
 
 [[constraint]]
   name = "github.com/prometheus/client_golang"

glide.yaml

@@ -1,7 +1,7 @@
 package: github.com/uber/jaeger-client-go
 import:
 - package: github.com/opentracing/opentracing-go
-  version: ^1.1
+  version: ^1.2
   subpackages:
   - ext
   - log
@@ -18,7 +18,9 @@ import:
 - package: github.com/uber-go/atomic
   version: ^1
 - package: github.com/prometheus/client_golang
-  version: ^1
+  version: 1.1
+- package: github.com/prometheus/procfs
+  version: 0.0.6
 testImport:
 - package: github.com/stretchr/testify
   subpackages:

jaeger_thrift_span_test.go

@@ -126,7 +126,7 @@ func TestBuildLogs(t *testing.T) {
 		{field: log.Uint64("k", 123), expected: []*j.Tag{{Key: "k", VType: j.TagType_LONG, VLong: &someLong}}},
 		{field: log.Float32("k", 123), expected: []*j.Tag{{Key: "k", VType: j.TagType_DOUBLE, VDouble: &someDouble}}},
 		{field: log.Float64("k", 123), expected: []*j.Tag{{Key: "k", VType: j.TagType_DOUBLE, VDouble: &someDouble}}},
-		{field: log.Error(errors.New(errString)), expected: []*j.Tag{{Key: "error", VType: j.TagType_STRING, VStr: &errString}}},
+		{field: log.Error(errors.New(errString)), expected: []*j.Tag{{Key: "error.object", VType: j.TagType_STRING, VStr: &errString}}},
 		{field: log.Object("k", someSlice), expected: []*j.Tag{{Key: "k", VType: j.TagType_STRING, VStr: &someSliceString}}},
 		{
 			field: log.Lazy(func(fv log.Encoder) {
@@ -146,7 +146,7 @@ func TestBuildLogs(t *testing.T) {
 			},
 			// this is a bit fragile, but ¯\_(ツ)_/¯
 			expected: []*j.Tag{
-				{Key: "error", VType: j.TagType_STRING, VStr: getStringPtr("non-even keyValues len: 1")},
+				{Key: "error.object", VType: j.TagType_STRING, VStr: getStringPtr("non-even keyValues len: 1")},
 				{Key: "function", VType: j.TagType_STRING, VStr: getStringPtr("LogKV")},
 			},
 		},
@@ -403,7 +403,8 @@ func compareTags(t *testing.T, expected, actual *j.Tag, testName string) {
 		return
 	}
 	if expected == nil || actual == nil {
-		assert.Fail(t, "one of the tags is nil", testName)
+		t.Logf("one of the tags is nil, test=%s, expected=%v, actual=%v", testName, expected, actual)
+		assert.Fail(t, "one of the tags is nil")
 		return
 	}
 	assert.Equal(t, expected.Key, actual.Key, testName)

zipkin_thrift_span_test.go

@@ -142,7 +142,7 @@ func TestThriftSpanLogs(t *testing.T) {
 		{fields: fields(log.Float32("something", 123)), expected: `{"something":"123.000000"}`},
 		{fields: fields(log.Float64("something", 123)), expected: `{"something":"123.000000"}`},
 		{fields: fields(log.Error(errors.New("drugs are baaad, m-k"))),
-			expected: `{"error":"drugs are baaad, m-k"}`},
+			expected: `{"error.object":"drugs are baaad, m-k"}`},
 		{fields: fields(log.Object("something", 123)), expected: `{"something":"123"}`},
 		{
 			fields: fields(log.Lazy(func(fv log.Encoder) {
@@ -161,7 +161,7 @@ func TestThriftSpanLogs(t *testing.T) {
 				sp.LogKV("non-even number of arguments")
 			},
 			// this is a bit fragile, but ¯\_(ツ)_/¯
-			expected: `{"error":"non-even keyValues len: 1","function":"LogKV"}`,
+			expected: `{"error.object":"non-even keyValues len: 1","function":"LogKV"}`,
 		},
 		{
 			logFunc: func(sp opentracing.Span) {