Update to lua 5.3.4

[daurnimator]

Released 2017-01-12

Though I'm curious why you're vendoring lua...

[sagebind]

It was intentionally switched to being bundled in #59. In general it was seen as a bad idea to fetch things from the network as part of a build script.

[therustmonk]

Is there still no official git repo of lua? We could use it as a submodule.

[daurnimator]

In general it was seen as a bad idea to fetch things from the network as part of a build script.

I wouldn't expect a build script to download anything either. It should use the system installed lua (if suitable/available) or instruct the user to provide a path to lua headers/library.

Is there still no official git repo of lua? We could use it as a submodule.

There is. http://github.com/lua/lua