TST: Fixed version comparison
This failed to skip for 3.5.x because the micro component made it False.


closes https://github.com/pandas-dev/pandas/issues/20468
# [Codecov](https://codecov.io/gh/pandas-dev/pandas/pull/20469?src=pr&el=h1) Report
> Merging [#20469](https://codecov.io/gh/pandas-dev/pandas/pull/20469?src=pr&el=desc) into [master](https://codecov.io/gh/pandas-dev/pandas/commit/53ad5c68b600f2929edd165c7b45e363c956144d?src=pr&el=desc) will **increase** coverage by `<.01%`.
> The diff coverage is `n/a`.

[![Impacted file tree graph](https://codecov.io/gh/pandas-dev/pandas/pull/20469/graphs/tree.svg?width=650&height=150&src=pr&token=eZ4WkYLtcO)](https://codecov.io/gh/pandas-dev/pandas/pull/20469?src=pr&el=tree)

```diff
@@            Coverage Diff             @@
##           master   #20469      +/-   ##
==========================================
+ Coverage   91.83%   91.84%   +<.01%     
==========================================
  Files         152      152              
  Lines       49231    49231              
==========================================
+ Hits        45213    45215       +2     
+ Misses       4018     4016       -2
```

| Flag | Coverage Δ | |
|---|---|---|
| #multiple | `90.22% <ø> (ø)` | :arrow_up: |
| #single | `41.83% <ø> (ø)` | :arrow_up: |

| [Impacted Files](https://codecov.io/gh/pandas-dev/pandas/pull/20469?src=pr&el=tree) | Coverage Δ | |
|---|---|---|
| [pandas/util/testing.py](https://codecov.io/gh/pandas-dev/pandas/pull/20469/diff?src=pr&el=tree#diff-cGFuZGFzL3V0aWwvdGVzdGluZy5weQ==) | `84.73% <0%> (+0.2%)` | :arrow_up: |

------

[Continue to review full report at Codecov](https://codecov.io/gh/pandas-dev/pandas/pull/20469?src=pr&el=continue).
> **Legend** - [Click here to learn more](https://docs.codecov.io/docs/codecov-delta)
> `Δ = absolute <relative> (impact)`, `ø = not affected`, `? = missing data`
> Powered by [Codecov](https://codecov.io/gh/pandas-dev/pandas/pull/20469?src=pr&el=footer). Last update [53ad5c6...291601e](https://codecov.io/gh/pandas-dev/pandas/pull/20469?src=pr&el=lastupdated). Read the [comment docs](https://docs.codecov.io/docs/pull-request-comments).
