Add support for Scalingo-20

Author: nwittstruck

README.md

@@ -15,7 +15,7 @@
 
 * Erlang - Prebuilt packages (17.5, 17.4, etc)
   * The full list of prebuilt packages can be found here: 
-    * gigalixir-20 or heroku-20 stacks: https://builds.hex.pm/builds/otp/ubuntu-20.04/builds.txt
+    * gigalixir-20, heroku-20 or scalingo-20 stacks: https://builds.hex.pm/builds/otp/ubuntu-20.04/builds.txt
     * heroku-22 stacks: https://builds.hex.pm/builds/otp/ubuntu-22.04/builds.txt
     * All other stacks: https://github.com/HashNuke/heroku-buildpack-elixir-otp-builds/blob/master/otp-versions
 * Elixir - Prebuilt releases (1.0.4, 1.0.3, etc) or prebuilt branches (master, v1.7, etc)

lib/canonical_version.sh

@@ -8,6 +8,9 @@ erlang_builds_url() {
     "heroku-22")
       erlang_builds_url="https://builds.hex.pm/builds/otp/ubuntu-22.04"
       ;;
+    "scalingo-20")
+      erlang_builds_url="https://repo.hex.pm/builds/otp/ubuntu-20.04"
+      ;;
     *)
       erlang_builds_url="https://s3.amazonaws.com/heroku-buildpack-elixir/erlang/cedar-14"
       ;;
@@ -26,6 +29,10 @@ fetch_erlang_versions() {
       url="https://builds.hex.pm/builds/otp/ubuntu-20.04/builds.txt"
       curl -s "$url" | awk '/^OTP-([0-9.]+ )/ {print substr($1,5)}'
       ;;
+    "scalingo-20")
+      url="https://repo.hex.pm/builds/otp/ubuntu-20.04/builds.txt"
+      curl -s "$url" | awk '/^OTP-([0-9.]+ )/ {print substr($1,5)}'
+      ;;
     "heroku-22")
       url="https://builds.hex.pm/builds/otp/ubuntu-22.04/builds.txt"
       curl -s "$url" | awk '/^OTP-([0-9.]+ )/ {print substr($1,5)}'