Revert "Reuse installed rebar and rebar3 for mix"

This reverts commit b5da5b66b8e2b2f0fe86ca142f1c45a63b5f9e0f.
diff --git a/Makefile b/Makefile
index 957d54d..e9ab1d2 100644
--- a/Makefile
+++ b/Makefile
@@ -244,7 +244,7 @@
 .PHONY: elixir-init
 elixir-init: MIX_ENV=test
 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
+	@mix local.rebar --force && mix local.hex --force && mix deps.get
 
 .PHONY: elixir-cluster-without-quorum
 elixir-cluster-without-quorum: export MIX_ENV=integration