add tests

[Bilal2453]

a bit of a late realisation but I just noticed we have no tests whatsoever. A list of tests I can think of

runtime related tests:

• luvibundle
• luvipath
• lenv
• winsvc (?)
• snapshot (?)
• miniz/lminiz (untested on its own)

build related tests:

• make sure all expected modules can be required (avoid lpeg's re module is no more available #306)
• make sure deps/requrie/deps/pretty-print are respected