## Bug description

<img width="696" alt="Screen Shot 2021-09-16 at 2 37 41 PM" src="https://user-images.githubusercontent.com/13460330/133689529-c4fffc7f-53f8-494e-b7a8-7fb656fd50e6.png">

## Expected behavior

Bars and labels always show on top of axes and gridlines.

## How to reproduce

1. https://app.posthog.com/insights?insight=FUNNELS&properties=%5B%5D&filter_test_accounts=false&events=%5B%7B%22id%22%3A%22%24pageview%22%2C%22name%22%3A%22%24pageview%22%2C%22type%22%3A%22events%22%2C%22order%22%3A0%7D%2C%7B%22id%22%3A%22%24pageview%22%2C%22name%22%3A%22%24pageview%22%2C%22type%22%3A%22events%22%2C%22order%22%3A1%7D%2C%7B%22id%22%3A%22%24pageview%22%2C%22name%22%3A%22%24pageview%22%2C%22type%22%3A%22events%22%2C%22order%22%3A2%7D%5D&actions=%5B%5D&exclusions=%5B%5D&interval=day&funnel_from_step=0&funnel_to_step=1&new_entity=%5B%5D&funnel_viz_type=time_to_convert&display=FunnelViz

## Environment

- [X] PostHog Cloud
- [X] self-hosted PostHog (ClickHouse-based), version/commit: _please provide_
- [X] self-hosted PostHog (Postgres-based, legacy), version/commit: _please provide_

## Additional context



#### *Thank you* for your bug report – we love squashing them!

ee/clickhouse/queries/funnels/test/test_funnel_time_to_convert.py
"funnel_to_step": 1,
                "funnel_window_days": 7,
                "bin_count": 7,
                "events": [
                    {"id": "step one", "order": 0},
                    {"id": "step two", "order": 1},
                    {"id": "step three", "order": 2},
                ],
            }
        )
        funnel_trends = ClickhouseFunnelTimeToConvert(filter, self.team, ClickhouseFunnel)
        results = funnel_trends.run()
        
        self.assertEqual(
            results,
            {
                "bins": [
                    (2220.0, 2),  
                    (13732.0, 0),  
                    (25244.0, 0),  
                    (36756.0, 0),
                    (48268.0, 0),
                    (59780.0, 0),
                    (71292.0, 1),  
                    (82804.0, 0),
                ],
                "average_conversion_time": 29_540,
            },
        )
    def test_auto_bin_count_total(self):