Move elixir source checks to a separate step

This is to help unblock 3.3 windows build so make check doesn't choke on
re-formatting elixir files for Windows.

Makefile

@@ -185,7 +185,7 @@ exunit: export ERL_LIBS = $(shell pwd)/src
 exunit: export ERL_AFLAGS = -config $(shell pwd)/rel/files/eunit.config
 exunit: export COUCHDB_QUERY_SERVER_JAVASCRIPT = $(shell pwd)/bin/couchjs $(shell pwd)/share/server/main.js
 exunit: export COUCHDB_TEST_ADMIN_PARTY_OVERRIDE=1
-exunit: couch elixir-init setup-eunit elixir-check-formatted elixir-credo
+exunit: couch elixir-init setup-eunit
 	@mix test --trace $(EXUNIT_OPTS)
 
 setup-eunit: export BUILDDIR = $(shell pwd)
@@ -235,50 +235,46 @@ python-black-update: .venv/bin/black
 .PHONY: elixir
 elixir: export MIX_ENV=integration
 elixir: export COUCHDB_TEST_ADMIN_PARTY_OVERRIDE=1
-elixir: elixir-init elixir-check-formatted elixir-credo devclean
+elixir: elixir-init devclean
 	@dev/run "$(TEST_OPTS)" -a adm:pass -n 1 \
 		--enable-erlang-views \
 		--locald-config test/elixir/test/config/test-config.ini \
 		--no-eval 'mix test --trace --exclude without_quorum_test --exclude with_quorum_test $(EXUNIT_OPTS)'
 
 .PHONY: elixir-init
-elixir-init: MIX_ENV=test
+elixir-init: MIX_ENV=integration
 elixir-init: config.erl
 	@mix local.rebar --force rebar ./bin/rebar && mix local.rebar --force rebar3 ./bin/rebar3 && mix local.hex --force && mix deps.get
 
 .PHONY: elixir-cluster-without-quorum
 elixir-cluster-without-quorum: export MIX_ENV=integration
-elixir-cluster-without-quorum: elixir-init elixir-check-formatted elixir-credo devclean
+elixir-cluster-without-quorum: elixir-init devclean
 	@dev/run -n 3 -q -a adm:pass \
 		--degrade-cluster 2 \
 		--no-eval 'mix test --trace --only without_quorum_test $(EXUNIT_OPTS)'
 
 .PHONY: elixir-cluster-with-quorum
 elixir-cluster-with-quorum: export MIX_ENV=integration
-elixir-cluster-with-quorum: elixir-init elixir-check-formatted elixir-credo devclean
+elixir-cluster-with-quorum: elixir-init devclean
 	@dev/run -n 3 -q -a adm:pass \
 		--degrade-cluster 1 \
 		--no-eval 'mix test --trace --only with_quorum_test $(EXUNIT_OPTS)'
 
 .PHONY: elixir-suite
 elixir-suite: export MIX_ENV=integration
 elixir-suite: export COUCHDB_TEST_ADMIN_PARTY_OVERRIDE=1
-elixir-suite: elixir-init elixir-check-formatted elixir-credo devclean
+elixir-suite: elixir-init devclean
 	@dev/run -n 1 -q -a adm:pass \
 		--enable-erlang-views \
 		--no-join \
 		--locald-config test/elixir/test/config/test-config.ini \
 		--erlang-config rel/files/eunit.config \
 		--no-eval 'mix test --trace --include test/elixir/test/config/suite.elixir --exclude test/elixir/test/config/skip.elixir'
 
-.PHONY: elixir-check-formatted
-elixir-check-formatted: elixir-init
+.PHONY: elixir-source-checks
+elixir-source-checks: export MIX_ENV=integration
+elixir-source-checks: elixir-init
 	@mix format --check-formatted
-
-# Credo is a static code analysis tool for Elixir.
-# We use it in our tests
-.PHONY: elixir-credo
-elixir-credo: elixir-init
 	@mix credo
 
 .PHONY: build-report

build-aux/Jenkinsfile.pr

@@ -185,6 +185,7 @@ pipeline {
           rm -rf apache-couchdb-*
           ./configure --skip-deps
           make erlfmt-check
+          make elixir-source-checks
           make python-black
         '''
       }

mix.exs

@@ -84,7 +84,7 @@ defmodule CouchDBTest.Mixfile do
 
   # Run "mix help deps" to learn about dependencies.
   defp deps() do
-    [
+    deps_list = [
       {:junit_formatter, "~> 3.0", only: [:dev, :test, :integration]},
       {:httpotion, ">= 3.1.3", only: [:dev, :test, :integration], runtime: false},
       {:excoveralls, "~> 0.12", only: :test},
@@ -94,6 +94,16 @@ defmodule CouchDBTest.Mixfile do
       {:ibrowse, path: path("ibrowse"), override: true},
       {:credo, "~> 1.6.4", only: [:dev, :test, :integration], runtime: false}
     ]
+
+    # Some deps may be missing during source check
+    # Besides we don't want to spend time checking them anyway
+    List.foldl([:b64url, :jiffy, :jwtf, :ibrowse], deps_list, fn dep, acc ->
+      if File.dir?(acc[dep][:path]) do
+        acc
+      else
+        List.keydelete(acc, dep, 0)
+      end
+    end)
   end
 
   defp path(app) do