Fix release CI

Author: danschultzer

.github/workflows/build.yml

@@ -42,7 +42,7 @@ jobs:
       HEX_API_KEY: ${{secrets.HEX_API_KEY}}
     steps:
       - uses: actions/checkout@v2
-      - uses: actions/setup-elixir@v1
+      - uses: erlef/setup-elixir@v1
         with:
           otp-version: 24.0
           elixir-version: 1.13