test('__ipairs is supported') are unassertive on travis's Lua 5.3 environment

[cpeosphoros]

They pass on 5.2.

I've noticed this on my fork, but it happens with pure 30log, too. I couldn't find the reason for that, though.

[airstruck]

The __pairs and __ipairs tests iterate tables with next and expect a particular sequence of values. The problem is next doesn't iterate in a predictable order, like pairs. If those tests pass reliably in any version of Lua, it's only by accident.

[cpeosphoros]

Indeed.

While working in https://github.com/cpeosphoros/30log-plus I've got a couple of situations where code fails in production but passes the tests (not specifically this pairs/ipairs test harness).

I'm working on rewriting/complementing some of the tests and will PR here the ones relative to situations where behavior is not purposely changed in 30log-plus.