rpc generation fix (#184)

* reactor alert

* optimize

* add test case

* update the target directory in case proto contains option

* fix missing comments and format code

tools/goctl/rpc/parser/test_option.proto

@@ -2,9 +2,10 @@ syntax = "proto3";
 
 package stream;
 
-option go_package="github.com/tal-tech/go-zero";
+option go_package = "github.com/tal-tech/go-zero";
 
-message placeholder{}
-service greet{
-  rpc hello(placeholder)returns(placeholder);
+message placeholder {}
+
+service greet {
+  rpc hello (placeholder) returns (placeholder);
 }