Access Token Duration (#188)

* Access Token Duration

- fixed the access token expiring too quickly; the cookie expiration needed to be extended.
  Not sure when this was broken, but I changed the duration a while back. Needs a test added.

* - switching to gambol99/goproxy until a fix upstream

vendor/github.com/elazarl/goproxy/proxy.go → vendor/github.com/gambol99/goproxy/proxy.go

@@ -32,9 +32,6 @@ type ProxyHttpServer struct {
 var hasPort = regexp.MustCompile(`:\d+$`)
 
 func copyHeaders(dst, src http.Header) {
-	for k, _ := range dst {
-		dst.Del(k)
-	}
 	for k, vs := range src {
 		for _, v := range vs {
 			dst.Add(k, v)