release r热更

cd tcp_server_0.1
./bin/tcp_server console进入erlang的shell
release_handler:which_releases().

看到的应该是0.1
然后解压0.2的包，安装进入

erl> release_handler:unpack_release("tcp_server_0.2").
erl> release_handler:install_release("0.2").
erl> release_handler:make_permanent("0.2").
erl> release_handler:which_releases().