Problem:
Not all Lua code is checked by stylua. Automating code-style is an
important mechanism for reducing time spent on accidental
(non-essential) complexity.
Solution:
- Enable lintlua for `test/unit/` directory.
- TODO: only `test/functional/` remains unchecked.
previous: 45fe4d11ad
previous: 517f0cc634
Eliminates lua-client and non-static libluv as test time dependencies
Note: the API for a public lua-client is not yet finished.
The interface needs to be adjusted to work in the embedded loop
of a nvim instance (to use it to talk between instances)
