Add buildpacks for rust

RoyalIcing · RoyalIcing · commit abc27759a6e7 · 2020-04-14T22:10:31.000+10:00
diff --git a/.buildpacks b/.buildpacks
@@ -0,0 +1,4 @@
+https://github.com/emk/heroku-buildpack-rust
+https://github.com/HashNuke/heroku-buildpack-elixir
+https://github.com/gjaldon/heroku-buildpack-phoenix-static
+https://github.com/gigalixir/gigalixir-buildpack-mix.git
