git-flow: fix head resource and better test

Formula/git-flow-avh.rb

@@ -1,8 +1,16 @@
 class GitFlowAvh < Formula
   desc "AVH edition of git-flow"
   homepage "https://github.com/petervanderdoes/gitflow-avh"
-  url "https://github.com/petervanderdoes/gitflow-avh/archive/1.9.1.tar.gz"
-  sha256 "7692c77744663c5243cdd390bef0a621caee92dde228b50ef97149fc1b54780d"
+
+  stable do
+    url "https://github.com/petervanderdoes/gitflow-avh/archive/1.9.1.tar.gz"
+    sha256 "7692c77744663c5243cdd390bef0a621caee92dde228b50ef97149fc1b54780d"
+
+    resource "completion" do
+      url "https://github.com/petervanderdoes/git-flow-completion/archive/0.5.1.tar.gz"
+      sha256 "5c8547a549dc623a8d57cfc22c3fa88588f5630da9dc6de9638e5b69da9d47d0"
+    end
+  end
 
   bottle do
     cellar :any_skip_relocation
@@ -19,11 +27,6 @@ class GitFlowAvh < Formula
     end
   end
 
-  resource "completion" do
-    url "https://github.com/petervanderdoes/git-flow-completion/archive/0.5.1.tar.gz"
-    sha256 "5c8547a549dc623a8d57cfc22c3fa88588f5630da9dc6de9638e5b69da9d47d0"
-  end
-
   depends_on "gnu-getopt"
 
   conflicts_with "git-flow"
@@ -43,6 +46,9 @@ class GitFlowAvh < Formula
   end
 
   test do
-    system "#{bin}/git-flow", "version"
+    system "git", "init"
+    system "#{bin}/git-flow", "init", "-d"
+    system "#{bin}/git-flow", "config"
+    assert_equal "develop", shell_output("git symbolic-ref --short HEAD").chomp
   end
 end