tests: clean up after bottle test

Fix minor regression in b55250c44eacd49646407b26a73753965d4d36d0. The
bottle is placed in the current working directory, is unaffected by the
the single teardown introduced in #475, and thus needs manual handling.

Closes #483.

Signed-off-by: Martin Afanasjew <martin@afanasjew.de>

Library/Homebrew/test/test_integration_cmds.rb

@@ -250,6 +250,8 @@ class IntegrationCommandTests < Homebrew::TestCase
     end
     assert_match(/testball-0\.1.*\.bottle\.tar\.gz/,
                   cmd_output("bottle", "--no-revision", "testball"))
+  ensure
+    FileUtils.rm_f Dir["testball-0.1*.bottle.tar.gz"]
   end
 
   def test_uninstall