Revert TraceExporter Default (#1012)

* Revert TraceExporter Default

* fix tests

config.dev.toml

@@ -131,7 +131,7 @@ HGRCPath = ""
 # TraceExporter is the service to which the data collected by OpenCensus can be exported to.
 # Possible values are: jaeger, datadog, and stackdriver.
 # Env overide: ATHENS_TRACE_EXPORTER
-TraceExporter = "jaeger"
+TraceExporter = ""
 
 # TraceExporterURL is the URL to which Athens populates distributed tracing
 # information such as Jaeger. In Stackdriver, use this as the GCP ProjectID.

pkg/config/config_test.go

@@ -221,7 +221,6 @@ func TestParseExampleConfig(t *testing.T) {
 		BasicAuthPass:    "",
 		Storage:          expStorage,
 		TraceExporterURL: "http://localhost:14268",
-		TraceExporter:    "jaeger",
 		StatsExporter:    "prometheus",
 	}