Update DataFrame.eq docstring
This was failing due to http://pandas.pydata.org/pandas-docs/version/0.24.0rc1/whatsnew/v0.24.0.html#dataframe-comparison-operations-broadcasting-changes

I'm surprised the doctests didn't catch this. @datapythonista, `pandas.DataFrame.eq` is included in the API docs at http://pandas-docs.github.io/pandas-docs-travis/api/generated/pandas.DataFrame.eq.html.  I believe it's because EX02 isn't passed in the code checks. @datapythonista do you know if that's deliberate?
I didn't quite understand what was the problem. But there are many validations that we can't add to the CI yet, because we have many cases still failing, `EX02` is one of them. It will take time until we can validate everything, there is a lot of work in that side. > I didn't quite understand what was the problem

We made an API change, and broke the example in the docs.

So not including `EX02` was indeed the problem. There does seem to be quite a few failures. I'll see if I can fix those up. Ah, sorry, I got it now. We've got two ways of running the doctests, `EX02` was mainly implemented with validating a single docstring in mind. As the validation is currently done directly with pytest. I see in `ci/code_checks.py` that `ops.py` is not one of the files we check. That's probably what makes more sense, adding it there if you're fixing the doctests. # [Codecov](https://codecov.io/gh/pandas-dev/pandas/pull/24774?src=pr&el=h1) Report
> Merging [#24774](https://codecov.io/gh/pandas-dev/pandas/pull/24774?src=pr&el=desc) into [master](https://codecov.io/gh/pandas-dev/pandas/commit/6d3565a5181b3d0fb8342e69dd1d21a98ac3d380?src=pr&el=desc) will **decrease** coverage by `<.01%`.
> The diff coverage is `n/a`.

[![Impacted file tree graph](https://codecov.io/gh/pandas-dev/pandas/pull/24774/graphs/tree.svg?width=650&token=eZ4WkYLtcO&height=150&src=pr)](https://codecov.io/gh/pandas-dev/pandas/pull/24774?src=pr&el=tree)

```diff
@@            Coverage Diff             @@
##           master   #24774      +/-   ##
==========================================
- Coverage   92.38%   92.38%   -0.01%     
==========================================
  Files         166      166              
  Lines       52363    52363              
==========================================
- Hits        48377    48376       -1     
- Misses       3986     3987       +1
```

| Flag | Coverage Δ | |
|---|---|---|
| #multiple | `90.81% <ø> (ø)` | :arrow_up: |
| #single | `42.91% <ø> (ø)` | :arrow_up: |

| [Impacted Files](https://codecov.io/gh/pandas-dev/pandas/pull/24774?src=pr&el=tree) | Coverage Δ | |
|---|---|---|
| [pandas/core/ops.py](https://codecov.io/gh/pandas-dev/pandas/pull/24774/diff?src=pr&el=tree#diff-cGFuZGFzL2NvcmUvb3BzLnB5) | `94.28% <ø> (ø)` | :arrow_up: |
| [pandas/util/testing.py](https://codecov.io/gh/pandas-dev/pandas/pull/24774/diff?src=pr&el=tree#diff-cGFuZGFzL3V0aWwvdGVzdGluZy5weQ==) | `88% <0%> (-0.1%)` | :arrow_down: |

------

[Continue to review full report at Codecov](https://codecov.io/gh/pandas-dev/pandas/pull/24774?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/24774?src=pr&el=footer). Last update [6d3565a...abb00ff](https://codecov.io/gh/pandas-dev/pandas/pull/24774?src=pr&el=lastupdated). Read the [comment docs](https://docs.codecov.io/docs/pull-request-comments).
 # [Codecov](https://codecov.io/gh/pandas-dev/pandas/pull/24774?src=pr&el=h1) Report
> Merging [#24774](https://codecov.io/gh/pandas-dev/pandas/pull/24774?src=pr&el=desc) into [master](https://codecov.io/gh/pandas-dev/pandas/commit/6d3565a5181b3d0fb8342e69dd1d21a98ac3d380?src=pr&el=desc) will **decrease** coverage by `<.01%`.
> The diff coverage is `n/a`.

[![Impacted file tree graph](https://codecov.io/gh/pandas-dev/pandas/pull/24774/graphs/tree.svg?width=650&token=eZ4WkYLtcO&height=150&src=pr)](https://codecov.io/gh/pandas-dev/pandas/pull/24774?src=pr&el=tree)

```diff
@@            Coverage Diff             @@
##           master   #24774      +/-   ##
==========================================
- Coverage   92.38%   92.38%   -0.01%     
==========================================
  Files         166      166              
  Lines       52363    52363              
==========================================
- Hits        48377    48376       -1     
- Misses       3986     3987       +1
```

| Flag | Coverage Δ | |
|---|---|---|
| #multiple | `90.81% <ø> (ø)` | :arrow_up: |
| #single | `42.91% <ø> (ø)` | :arrow_up: |

| [Impacted Files](https://codecov.io/gh/pandas-dev/pandas/pull/24774?src=pr&el=tree) | Coverage Δ | |
|---|---|---|
| [pandas/core/ops.py](https://codecov.io/gh/pandas-dev/pandas/pull/24774/diff?src=pr&el=tree#diff-cGFuZGFzL2NvcmUvb3BzLnB5) | `94.28% <ø> (ø)` | :arrow_up: |
| [pandas/util/testing.py](https://codecov.io/gh/pandas-dev/pandas/pull/24774/diff?src=pr&el=tree#diff-cGFuZGFzL3V0aWwvdGVzdGluZy5weQ==) | `88% <0%> (-0.1%)` | :arrow_down: |

------

[Continue to review full report at Codecov](https://codecov.io/gh/pandas-dev/pandas/pull/24774?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/24774?src=pr&el=footer). Last update [6d3565a...abb00ff](https://codecov.io/gh/pandas-dev/pandas/pull/24774?src=pr&el=lastupdated). Read the [comment docs](https://docs.codecov.io/docs/pull-request-comments).
 Unfortunately, we can't use `pytest --doctest-modules` on ops.py It seems pytest / doctest don't collect the `_flex_comp_method_*` docs.

It's not clear to be how best to handle this CI-wise. Pushing on fixing the exceptions in the docstrings is probably the best path forward. thanks @TomAugspurger 