client: add proxy option (#1885)

* client: add proxy option

* client: add WithProxy CallOption

* use address option

* ProxyAddress => Proxy

util/net/net_test.go

@@ -2,7 +2,6 @@ package net
 
 import (
 	"net"
-	"os"
 	"testing"
 )
 
@@ -25,38 +24,3 @@ func TestListen(t *testing.T) {
 	// Expect addr DO NOT has extra ":" at the end!
 
 }
-
-// TestProxyEnv checks whether we have proxy/network settings in env
-func TestProxyEnv(t *testing.T) {
-	service := "foo"
-	address := []string{"bar"}
-
-	s, a, ok := Proxy(service, address)
-	if ok {
-		t.Fatal("Should not have proxy", s, a, ok)
-	}
-
-	test := func(key, val, expectSrv, expectAddr string) {
-		// set env
-		os.Setenv(key, val)
-
-		s, a, ok := Proxy(service, address)
-		if !ok {
-			t.Fatal("Expected proxy")
-		}
-		if len(expectSrv) > 0 && s != expectSrv {
-			t.Fatal("Expected proxy service", expectSrv, "got", s)
-		}
-		if len(expectAddr) > 0 {
-			if len(a) == 0 || a[0] != expectAddr {
-				t.Fatal("Expected proxy address", expectAddr, "got", a)
-			}
-		}
-
-		os.Unsetenv(key)
-	}
-
-	test("MICRO_PROXY", "service", "go.micro.proxy", "")
-	test("MICRO_NETWORK", "service", "go.micro.network", "")
-	test("MICRO_NETWORK_ADDRESS", "10.0.0.1:8081", "", "10.0.0.1:8081")
-}