remove external files

Signed-off-by: 高汝彤 <rutong.grt@alibaba-inc.com>

.idea/vcs.xml

@@ -1,6 +0,0 @@
-<?xml version="1.0" encoding="UTF-8"?>
-<project version="4">
-  <component name="VcsDirectoryMappings">
-    <mapping directory="$PROJECT_DIR$" vcs="Git" />
-  </component>
-</project>

helloworld.go

@@ -1 +0,0 @@
-package alibaba_cloud_sdk_go