style(lua): add file head

lua/spacevim/api.lua

@@ -1,7 +1,15 @@
-local api = {}
-function api.import(name)
+--=============================================================================
+-- api.lua --- lua api plugin
+-- Copyright (c) 2016-2019 Wang Shidong & Contributors
+-- Author: Wang Shidong < wsdjeg@outlook.com >
+-- URL: https://spacevim.org
+-- License: GPLv3
+--=============================================================================
+
+local M = {}
+
+function M.import(name)
  return require('spacevim.api.' .. name)   
 end
 
-
-return api
+return M

lua/spacevim/api/logger.lua

@@ -1,9 +1,12 @@
-local fn = nil
-if vim.fn == nil then
-    fn = require('spacevim').fn
-else
-    fn = vim.fn
-end
+--=============================================================================
+-- logger.lua --- logger api implemented in lua
+-- Copyright (c) 2016-2019 Wang Shidong & Contributors
+-- Author: Wang Shidong < wsdjeg@outlook.com >
+-- URL: https://spacevim.org
+-- License: GPLv3
+--=============================================================================
+
+local fn = vim.fn or require('spacevim').fn
 
 local cmd = require('spacevim').cmd
 

lua/spacevim/logger.lua

@@ -1,3 +1,12 @@
+--=============================================================================
+-- logger.lua --- logger implemented in lua
+-- Copyright (c) 2016-2019 Wang Shidong & Contributors
+-- Author: Wang Shidong < wsdjeg@outlook.com >
+-- URL: https://spacevim.org
+-- License: GPLv3
+--=============================================================================
+
+
 local M = {}
 
 local logger = require('spacevim.api').import('logger')