telemetry: add tracing

- telemetry/tace: add traces throughout code
- telemetry/metrics: nest metrics and trace under telemetry
- telemetry/tace: add service name span to HTTPMetricsHandler.
- telemetry/metrics: removed chain dependency middleware_tests.
- telemetry/metrics: wrap and encapsulate variatic view registration.
- telemetry/tace: add jaeger support for tracing.
- cmd/pomerium: move `parseOptions` to internal/config.
- cmd/pomerium: offload server handling to httputil and sub pkgs.
- httputil: standardize creation/shutdown of http listeners.
- httputil: prefer curve X25519 to P256 when negotiating TLS.
- fileutil: use standardized Getw

Signed-off-by: Bobby DeSimone <bobbydesimone@gmail.com>

internal/fileutil/fileutil_test.go

@@ -1,6 +1,9 @@
-package fileutil // import "github.com/pomerium/pomerium/internal/fileutil"
+package fileutil
 
-import "testing"
+import (
+	"strings"
+	"testing"
+)
 
 func TestIsReadableFile(t *testing.T) {
 
@@ -27,3 +30,19 @@ func TestIsReadableFile(t *testing.T) {
 		})
 	}
 }
+
+func TestGetwd(t *testing.T) {
+	tests := []struct {
+		name string
+		want string
+	}{
+		{"most basic example", "internal/fileutil"},
+	}
+	for _, tt := range tests {
+		t.Run(tt.name, func(t *testing.T) {
+			if got := Getwd(); strings.Contains(tt.want, got) {
+				t.Errorf("Getwd() = %v, want %v", got, tt.want)
+			}
+		})
+	}
+}