Port etags tests into elixir test suite

[jjrodrig]

Overview

This PR ports etags_head test into exlixir test suite. I've checked the etags_views.js but it currently disabled in the js test suite so I have not included it in the port.

Testing recommendations

make elixir tests=test/elixir/test/etags_head.exs

Related Issues or Pull Requests

Checklist

• Code is written and works correctly
• Changes are covered by tests
• Any new configurable parameters are documented in rel/overlay/etc/default.ini
• A PR for documentation changes has been made in https://github.com/apache/couchdb-documentation

[nickva]

@jjrodrig thank you for your contribution

Test looks good. I added two small fixes to it:

diff --git a/test/elixir/lib/couch.ex b/test/elixir/lib/couch.ex
index 994b68173..3aef07f01 100644
--- a/test/elixir/lib/couch.ex
+++ b/test/elixir/lib/couch.ex
@@ -110,7 +110,7 @@ defmodule Couch do
     end
   end

-  def process_response_body(headers, body) when body == [] do
+  def process_response_body(_headers, body) when body == [] do
     ""
   end

diff --git a/test/javascript/tests/etags_head.js b/test/javascript/tests/etags_head.js
index 9faca4af6..6cb99e40d 100644
--- a/test/javascript/tests/etags_head.js
+++ b/test/javascript/tests/etags_head.js
@@ -11,6 +11,7 @@
 // the License.

 couchTests.etags_head = function(debug) {
+  return console.log('done in tests=test/elixir/test/etags_head_test.exs');
   var db_name = get_random_db_name();
   var db = new CouchDB(db_name, {"X-Couch-Full-Commit":"false"});
   db.createDb();

Then squashed them into one commit and pushed them to the new PR #2469

[nickva]

Nice work. Thank you.

I'll move rebase and fixed up the changes then merge them from a separate PR (since I can't push to your branch)