Clean up tests to stop people copy and pasting the wrong examples

test/handler/test_dafny_handler.vader

@@ -1,5 +1,10 @@
-Execute(The Dafny handler should parse output correctly):
+Before:
   runtime ale_linters/dafny/dafny.vim
+
+After:
+  call ale#linter#Reset()
+
+Execute(The Dafny handler should parse output correctly):
   AssertEqual
   \ [
   \   {
@@ -21,6 +26,3 @@ Execute(The Dafny handler should parse output correctly):
   \ 'File.dfy(123,45): Error BP5002: A precondition for this call might not hold.',
   \ 'File.dfy(678,90): Related location: This is the precondition that might not hold.'
   \ ])
-
-After:
-  call ale#linter#Reset()