temp: ensure existance of tmp dir

Signed-off-by: Ulysse Buonomo <[email protected]>

Author: BuonOmo

test/cases/helper_cockroachdb.rb

@@ -133,6 +133,8 @@ def teardown
 
   def after_run
     is = @@passed ? "innocent" : "culprit"
+    FileUtils.mkdir_p("tmp")
+    FileUtils.touch("tmp/culprits.txt")
     File.write("tmp/culprits.txt", @@tests_before.map{"#{_1} #{is}"}.join("\n") + "\n")
   end
 end