Doesn't detect files with shebang

Atom won't detect files that don't have the extension '.lua' even if the file begins with a lua shebang.

If a file begins with
`#!/usr/bin/lua5`
`#!/usr/bin/lua5.1`
`#!/usr/bin/lua5.2`
etc., Atom should detect it and provide syntax highlighting, the same way it does for a Python file with the shebang
`#!/usr/bin/python3`