quickly generating rpc demo service (#60)

* add execute files

* add protoc-osx

* add rpc generation

* add rpc generation

* add: rpc template generation

* add README.md

* format error

* reactor templatex.go

* update project.go & README.md

* add: quickly generate rpc service

tools/goctl/rpc/gen/gomod.go

@@ -0,0 +1,22 @@
+package gen
+
+import (
+	"fmt"
+
+	"github.com/tal-tech/go-zero/core/logx"
+	"github.com/tal-tech/go-zero/tools/goctl/rpc/execx"
+)
+
+func (g *defaultRpcGenerator) initGoMod() error {
+	if !g.Ctx.IsInGoEnv {
+		projectDir := g.dirM[dirTarget]
+		cmd := fmt.Sprintf("go mod init %s", g.Ctx.ProjectName.Source())
+		output, err := execx.Run(fmt.Sprintf(cmd), projectDir)
+		if err != nil {
+			logx.Error(err)
+			return err
+		}
+		g.Ctx.Info(output)
+	}
+	return nil
+}