json dependency

[claytonsilva]

i have problem using this module, this depends on module 'json'

2017/11/17 21:04:56 [error] 49#49: init_by_lua_file error: /lua/stats/init.lua:1: module 'json' not found:
	no field package.preload['json']
	no file '/lua/json.lua'
	no file '/usr/local/openresty/site/lualib/json.ljbc'
	no file '/usr/local/openresty/site/lualib/json/init.ljbc'
	no file '/usr/local/openresty/lualib/json.ljbc'
	no file '/usr/local/openresty/lualib/json/init.ljbc'
	no file '/usr/local/openresty/site/lualib/json.lua'
	no file '/usr/local/openresty/site/lualib/json/init.lua'
	no file '/usr/local/openresty/lualib/json.lua'
	no file '/usr/local/openresty/lualib/json/init.lua'
	no file './json.lua'
	no file '/usr/local/openresty/luajit/share/luajit-2.1.0-beta3/json.lua'
	no file '/usr/local/share/lua/5.1/json.lua'
	no file '/usr/local/share/lua/5.1/json/init.lua'
	no file '/usr/local/openresty/luajit/share/lua/5.1/json.lua'
	no file '/usr/local/openresty/luajit/share/lua/5.1/json/init.lua'
	no file '/etc/nginx/lua/json.so'
	no file '/usr/local/openresty/site/lualib/json.so'
	no file '/usr/local/openresty/lualib/json.so'
	no file './json.so'
	no file '/usr/local/lib/lua/5.1/json.so'
	no file '/usr/local/openresty/luajit/lib/lua/5.1/json.so'
	no file '/usr/local/lib/lua/5.1/loadall.so'
stack traceback:
	[C]: in function 'require'
	/lua/stats/init.lua:1: in main chunk