allow to generate standalone code

Signed-off-by: Vasiliy Tolstov <v.tolstov@unistack.org>

micro.go

@@ -14,7 +14,12 @@ func (g *Generator) microGenerate(component string, plugin *protogen.Plugin) err
 		}
 
 		gname := file.GeneratedFilenamePrefix + "_" + component + ".pb.go"
-		gfile := plugin.NewGeneratedFile(gname, file.GoImportPath)
+
+		path := file.GoImportPath
+		if g.standalone {
+			path = "."
+		}
+		gfile := plugin.NewGeneratedFile(gname, path)
 
 		gfile.P("// Code generated by protoc-gen-micro")
 		gfile.P("// source: ", *file.Proto.Name)