elm-format 0.8.0

update tests for 0.8.0

- elm-format 0.8.0 doesn't provide elm-format-0.17 anymore, but only
  elm-format-0.18 and elm-format-0.19

Closes #31628.

Signed-off-by: Dominyk Tiller <dominyktiller@gmail.com>

Formula/elm-format.rb

@@ -6,9 +6,8 @@ class ElmFormat < Formula
   desc "Elm source code formatter, inspired by gofmt"
   homepage "https://github.com/avh4/elm-format"
   url "https://github.com/avh4/elm-format.git",
-      :tag => "0.6.1-alpha",
-      :revision => "24cbc66245289dd3ca5c08a14e86358dc039fcf3"
-  version "0.6.1-alpha"
+      :tag => "0.8.0",
+      :revision => "f19ac28046d7e83ff95f845849c033cc616f1bd6"
   head "https://github.com/avh4/elm-format.git"
 
   bottle do
@@ -47,6 +46,7 @@ class ElmFormat < Formula
       main = text "Hello, world!"
     EOS
 
-    system bin/"elm-format-0.17", testpath/"Hello.elm", "--yes"
+    system bin/"elm-format-0.18", testpath/"Hello.elm", "--yes"
+    system bin/"elm-format-0.19", testpath/"Hello.elm", "--yes"
   end
 end