Don't write the HTML output to a hardcoded file

All formatters should play nice with the `-o` option.
Clean up AndOr spec

Some spec examples were testing how Parser parses code, not RuboCop's
behavior.
Handle post-conditional `while` and `until` in AndOr
Merge pull request #1317 from yujinakayama/and-or-in-conditional

Handle post-conditional `while` and `until` in AndOr