internal/config: refactor option parsing

- authorize: build whitelist from policy's URLs instead of strings.
- internal/httputil: merged httputil and https package.
- internal/config: merged config and policy packages.
- internal/metrics: removed unused measure struct.
- proxy/clients: refactor Addr fields to be urls.
- proxy: remove unused extend deadline function.
- proxy: use handler middleware for reverse proxy leg.
- proxy: change the way websocket requests are made (route based).

General improvements
- omitted value from range in several cases where for loop could be simplified.
- added error checking to many tests.
- standardize url parsing.
- remove unnecessary return statements.

- proxy: add self-signed certificate support. #179
- proxy: add skip tls certificate verification. #179
- proxy: Refactor websocket support to be route based. #204

internal/metrics/middleware_test.go

@@ -13,12 +13,6 @@ import (
 	"go.opencensus.io/stats/view"
 )
 
-type measure struct {
-	Name    string
-	Tags    map[string]string
-	Measure int
-}
-
 func newTestMux() http.Handler {
 	mux := http.NewServeMux()
 	mux.HandleFunc("/good", func(w http.ResponseWriter, r *http.Request) {