Move "lsh_buckets" class to the left

[romainfrancois]

Moving the custom class to the left prevents a failure with dplyr 1.0.0.

[romainfrancois]

Also using tibble::tibble() instead of dplyr::data_frame() which has been deprecated for some time.

We also see a few other deprecation messages that are not handled by this pull request at this point.

────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────
test-lsh.R:9: warning: (unknown)
`mutate_()` is deprecated as of dplyr 0.7.0.
Please use `mutate()` instead.
See vignette('programming') for more help
This warning is displayed once every 8 hours.
Call `lifecycle::last_warnings()` to see where this warning was generated.

test-lsh.R:9: warning: (unknown)
`group_by_()` is deprecated as of dplyr 0.7.0.
Please use `group_by()` instead.
See vignette('programming') for more help
This warning is displayed once every 8 hours.
Call `lifecycle::last_warnings()` to see where this warning was generated.

test-lsh.R:9: warning: (unknown)
`summarise_()` is deprecated as of dplyr 0.7.0.
Please use `summarise()` instead.
This warning is displayed once every 8 hours.
Call `lifecycle::last_warnings()` to see where this warning was generated.

test-lsh.R:9: warning: (unknown)
`select_()` is deprecated as of dplyr 0.7.0.
Please use `select()` instead.
This warning is displayed once every 8 hours.
Call `lifecycle::last_warnings()` to see where this warning was generated.

test-lsh.R:10: warning: (unknown)
`filter_()` is deprecated as of dplyr 0.7.0.
Please use `filter()` instead.
See vignette('programming') for more help
This warning is displayed once every 8 hours.
Call `lifecycle::last_warnings()` to see where this warning was generated.

test-lsh.R:10: warning: (unknown)
`arrange_()` is deprecated as of dplyr 0.7.0.
Please use `arrange()` instead.
See vignette('programming') for more help
This warning is displayed once every 8 hours.
Call `lifecycle::last_warnings()` to see where this warning was generated.

test-lsh.R:10: warning: (unknown)
`distinct_()` is deprecated as of dplyr 0.7.0.
Please use `distinct()` instead.
See vignette('programming') for more help
This warning is displayed once every 8 hours.
Call `lifecycle::last_warnings()` to see where this warning was generated.