Elixir test suite has landed on master!

[Joan Touzet <wo...@apache.org>]

In case you're not on notifications@, you may have missed that the
Elixir test suite has just landed on master.

This is the heroic effort of many people to modernize our aging
JavaScript test suite by converting it to Elixir. The work is
ongoing, and if you know Elixir (or want to learn it), we'd love
your help!

Replacing the JS test suite with an Elixir one is a key step in
our long term strategy to mitigate against our dependency on
SpiderMonkey 1.8.5. It also gives us a much richer environment in
which we can build and run tests.

At the moment, this test suite is not run by the `make check`
command. You must run `make elixir` to run the Elixir test suite.
It's our intent to move `make check` over to the elixir tests
as soon as there is feature parity between the JS and Elixir
suites.

If you do not have the dependencies installed that you need to
run Elixir, you can use the scripts in our apache/couchdb-ci
repository to install them for you. (Thanks, Ilya!) Clone
the repo, and run the `bin/install-elixir.sh` script
with root permissions. You must have `git`, `unzip` and `wget`
installed for this script to work.

Thanks again to everyone who helped us get this far!
-Joan