The directory name could contain special characters that trips up the
matching used by find. Instead, let's just make sure that the filename
starts with the directory name.
Used
sed -r -i -e '/ helpers =/ s/$/\nlocal itp = helpers.gen_itp(it)/; s/^(\s*)it\(/\1itp(/' test/unit/**/*_spec.lua
to alter all tests. Locally they all run fine now.
Reasoning:
1. General: state from one test should not affect other tests.
2. Local: travis build is failing with something which may be an output of
garbage collector. This should prevent state of the garbage collector from
interferring as well.
It's possible that the first test encounters a temp directory with files
in it, due to a previous test causing the first test to fail. Instead,
let's clean up before and after the test to make sure the temp area is
pristine before and after the test.
