It is otherwise impossible to determine which test failed sanitizer/valgrind
check. test/functional/helpers.lua module return was changed so that tests which
do not provide after_each function to get new check will automatically fail.
-1 is index past the end, and -2 is the index of the last element.
This eliminates the need for include_start/include_end.
Allow the handling of out-of-bounds to be configurable.
Sanity API checks made by the python-client in the api-python travis target were
converted to lua and will now live in this repository. This will simplify
performing breaking changes to the API as it won't be necessary to send parallel
PRs the python-client.
