Update example to use jaeger exporter and update Readme (#143)

* update http example to use jaeger exporter and sdk.

* update image location.

* remove extra parameters for jaeger.

sdk/trace/export.go

@@ -86,7 +86,7 @@ type SpanData struct {
 	// from StartTime by the duration of the span.
 	EndTime time.Time
 	// The values of Attributes each have type string, bool, or int64.
-	Attributes               map[string]interface{}
+	Attributes               []core.KeyValue
 	MessageEvents            []Event
 	Links                    []apitrace.Link
 	Status                   codes.Code

sdk/trace/span.go

@@ -272,13 +272,14 @@ func (s *span) interfaceArrayToMessageEventArray() []Event {
 	return messageEventArr
 }
 
-func (s *span) lruAttributesToAttributeMap() map[string]interface{} {
-	attributes := make(map[string]interface{})
+func (s *span) lruAttributesToAttributeMap() []core.KeyValue {
+	attributes := make([]core.KeyValue, 0, s.lruAttributes.simpleLruMap.Len())
 	for _, key := range s.lruAttributes.simpleLruMap.Keys() {
 		value, ok := s.lruAttributes.simpleLruMap.Get(key)
 		if ok {
 			key := key.(core.Key)
-			attributes[key.Name] = value
+			value := value.(core.Value)
+			attributes = append(attributes, core.KeyValue{Key: key, Value: value})
 		}
 	}
 	return attributes

sdk/trace/trace_test.go

@@ -186,9 +186,12 @@ func TestSetSpanAttributes(t *testing.T) {
 			TraceID:      tid,
 			TraceOptions: 0x1,
 		},
-		ParentSpanID:    sid,
-		Name:            "span0",
-		Attributes:      map[string]interface{}{"key1": core.Value{Type: core.STRING, String: "value1"}},
+		ParentSpanID: sid,
+		Name:         "span0",
+		Attributes: []core.KeyValue{{
+			Key:   core.Key{Name: "key1"},
+			Value: core.Value{Type: core.STRING, String: "value1"},
+		}},
 		HasRemoteParent: true,
 	}
 	if diff := cmp.Diff(got, want); diff != "" {
@@ -217,9 +220,16 @@ func TestSetSpanAttributesOverLimit(t *testing.T) {
 		},
 		ParentSpanID: sid,
 		Name:         "span0",
-		Attributes: map[string]interface{}{
-			"key1": core.Value{Type: core.STRING, String: "value3"},
-			"key4": core.Value{Type: core.STRING, String: "value4"}},
+		Attributes: []core.KeyValue{
+			{
+				Key:   core.Key{Name: "key1"},
+				Value: core.Value{Type: core.STRING, String: "value3"},
+			},
+			{
+				Key:   core.Key{Name: "key4"},
+				Value: core.Value{Type: core.STRING, String: "value4"},
+			},
+		},
 		HasRemoteParent:       true,
 		DroppedAttributeCount: 1,
 	}