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/config/helpers.go

@@ -1,16 +1,5 @@
 package config // import "github.com/pomerium/pomerium/internal/config"
 
-import "os"
-
-// findPwd returns best guess at current working directory
-func findPwd() string {
-	p, err := os.Getwd()
-	if err != nil {
-		return "."
-	}
-	return p
-}
-
 // IsValidService checks to see if a service is a valid service mode
 func IsValidService(s string) bool {
 	switch s {