Interval dtype fix
- [x] closes #25283
- [x] test added to ensure pd.api.types.IntervalDtype('IntervalA') throws TypeError
- [x] test added to ensure pd.api.types.IntervalDtype.construct_from_string('IntervalA') throws TypeError
- [x] test added to ensure pd.api.types.IntervalDtype.is_dtype('IntervalA') returns false
- [x] passes `git diff upstream/master -u -- "*.py" | flake8 --diff`
- [x] test added to ensure * `Series(['IntervalA', 'IntervalB', 'IntervalC']) == 'IntervalA'` returns the expected boolean series
- [x] what's new note added to doc/source/whatsnew/v0.24.2.rst documenting regression fix
on it 👍  existing unit tests broke anyways, ill ping this thread when have things cleaned up Hello @zangell44! Thanks for updating the PR.

 - In the file [`pandas/core/dtypes/dtypes.py`](https://github.com/pandas-dev/pandas/blob/1ed7f8cc474923296d545fda94e61c8226d3fac9/pandas/core/dtypes/dtypes.py), following are the PEP8 issues :

> [Line 940:17](https://github.com/pandas-dev/pandas/blob/1ed7f8cc474923296d545fda94e61c8226d3fac9/pandas/core/dtypes/dtypes.py#L940): [E117](https://duckduckgo.com/?q=pep8%20E117) over-indented







##### Comment last updated on February 20, 2019 at 02:46 Hours UTC # [Codecov](https://codecov.io/gh/pandas-dev/pandas/pull/25338?src=pr&el=h1) Report
> Merging [#25338](https://codecov.io/gh/pandas-dev/pandas/pull/25338?src=pr&el=desc) into [master](https://codecov.io/gh/pandas-dev/pandas/commit/4a20d5b9e526435a53b7cb1dc0a819299d31f040?src=pr&el=desc) will **decrease** coverage by `50%`.
> The diff coverage is `75%`.

[![Impacted file tree graph](https://codecov.io/gh/pandas-dev/pandas/pull/25338/graphs/tree.svg?width=650&token=eZ4WkYLtcO&height=150&src=pr)](https://codecov.io/gh/pandas-dev/pandas/pull/25338?src=pr&el=tree)

```diff
@@             Coverage Diff             @@
##           master   #25338       +/-   ##
===========================================
- Coverage   91.73%   41.72%   -50.01%     
===========================================
  Files         173      173               
  Lines       52839    52843        +4     
===========================================
- Hits        48472    22051    -26421     
- Misses       4367    30792    +26425
```

| Flag | Coverage Δ | |
|---|---|---|
| #multiple | `?` | |
| #single | `41.72% <75%> (ø)` | :arrow_up: |

| [Impacted Files](https://codecov.io/gh/pandas-dev/pandas/pull/25338?src=pr&el=tree) | Coverage Δ | |
|---|---|---|
| [pandas/core/dtypes/dtypes.py](https://codecov.io/gh/pandas-dev/pandas/pull/25338/diff?src=pr&el=tree#diff-cGFuZGFzL2NvcmUvZHR5cGVzL2R0eXBlcy5weQ==) | `73.78% <75%> (-21.81%)` | :arrow_down: |
| [pandas/io/formats/latex.py](https://codecov.io/gh/pandas-dev/pandas/pull/25338/diff?src=pr&el=tree#diff-cGFuZGFzL2lvL2Zvcm1hdHMvbGF0ZXgucHk=) | `0% <0%> (-100%)` | :arrow_down: |
| [pandas/core/categorical.py](https://codecov.io/gh/pandas-dev/pandas/pull/25338/diff?src=pr&el=tree#diff-cGFuZGFzL2NvcmUvY2F0ZWdvcmljYWwucHk=) | `0% <0%> (-100%)` | :arrow_down: |
| [pandas/io/sas/sas\_constants.py](https://codecov.io/gh/pandas-dev/pandas/pull/25338/diff?src=pr&el=tree#diff-cGFuZGFzL2lvL3Nhcy9zYXNfY29uc3RhbnRzLnB5) | `0% <0%> (-100%)` | :arrow_down: |
| [pandas/tseries/plotting.py](https://codecov.io/gh/pandas-dev/pandas/pull/25338/diff?src=pr&el=tree#diff-cGFuZGFzL3RzZXJpZXMvcGxvdHRpbmcucHk=) | `0% <0%> (-100%)` | :arrow_down: |
| [pandas/tseries/converter.py](https://codecov.io/gh/pandas-dev/pandas/pull/25338/diff?src=pr&el=tree#diff-cGFuZGFzL3RzZXJpZXMvY29udmVydGVyLnB5) | `0% <0%> (-100%)` | :arrow_down: |
| [pandas/io/formats/html.py](https://codecov.io/gh/pandas-dev/pandas/pull/25338/diff?src=pr&el=tree#diff-cGFuZGFzL2lvL2Zvcm1hdHMvaHRtbC5weQ==) | `0% <0%> (-99.35%)` | :arrow_down: |
| [pandas/core/groupby/categorical.py](https://codecov.io/gh/pandas-dev/pandas/pull/25338/diff?src=pr&el=tree#diff-cGFuZGFzL2NvcmUvZ3JvdXBieS9jYXRlZ29yaWNhbC5weQ==) | `0% <0%> (-95.46%)` | :arrow_down: |
| [pandas/io/sas/sas7bdat.py](https://codecov.io/gh/pandas-dev/pandas/pull/25338/diff?src=pr&el=tree#diff-cGFuZGFzL2lvL3Nhcy9zYXM3YmRhdC5weQ==) | `0% <0%> (-91.17%)` | :arrow_down: |
| [pandas/io/sas/sas\_xport.py](https://codecov.io/gh/pandas-dev/pandas/pull/25338/diff?src=pr&el=tree#diff-cGFuZGFzL2lvL3Nhcy9zYXNfeHBvcnQucHk=) | `0% <0%> (-90.15%)` | :arrow_down: |
| ... and [131 more](https://codecov.io/gh/pandas-dev/pandas/pull/25338/diff?src=pr&el=tree-more) | |

------

[Continue to review full report at Codecov](https://codecov.io/gh/pandas-dev/pandas/pull/25338?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/25338?src=pr&el=footer). Last update [4a20d5b...c0818b6](https://codecov.io/gh/pandas-dev/pandas/pull/25338?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/25338?src=pr&el=h1) Report
> Merging [#25338](https://codecov.io/gh/pandas-dev/pandas/pull/25338?src=pr&el=desc) into [master](https://codecov.io/gh/pandas-dev/pandas/commit/659e0cae6be2d7ab3370cc7d8ab936bc3ee1b159?src=pr&el=desc) will **increase** coverage by `<.01%`.
> The diff coverage is `100%`.

[![Impacted file tree graph](https://codecov.io/gh/pandas-dev/pandas/pull/25338/graphs/tree.svg?width=650&token=eZ4WkYLtcO&height=150&src=pr)](https://codecov.io/gh/pandas-dev/pandas/pull/25338?src=pr&el=tree)

```diff
@@            Coverage Diff             @@
##           master   #25338      +/-   ##
==========================================
+ Coverage   91.73%   91.73%   +<.01%     
==========================================
  Files         173      173              
  Lines       52839    52841       +2     
==========================================
+ Hits        48472    48476       +4     
+ Misses       4367     4365       -2
```

| Flag | Coverage Δ | |
|---|---|---|
| #multiple | `90.3% <100%> (ø)` | :arrow_up: |
| #single | `41.72% <75%> (ø)` | :arrow_up: |

| [Impacted Files](https://codecov.io/gh/pandas-dev/pandas/pull/25338?src=pr&el=tree) | Coverage Δ | |
|---|---|---|
| [pandas/core/dtypes/dtypes.py](https://codecov.io/gh/pandas-dev/pandas/pull/25338/diff?src=pr&el=tree#diff-cGFuZGFzL2NvcmUvZHR5cGVzL2R0eXBlcy5weQ==) | `96.1% <100%> (+0.51%)` | :arrow_up: |
| [pandas/core/generic.py](https://codecov.io/gh/pandas-dev/pandas/pull/25338/diff?src=pr&el=tree#diff-cGFuZGFzL2NvcmUvZ2VuZXJpYy5weQ==) | `94.16% <0%> (-0.01%)` | :arrow_down: |

------

[Continue to review full report at Codecov](https://codecov.io/gh/pandas-dev/pandas/pull/25338?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/25338?src=pr&el=footer). Last update [659e0ca...1ed7f8c](https://codecov.io/gh/pandas-dev/pandas/pull/25338?src=pr&el=lastupdated). Read the [comment docs](https://docs.codecov.io/docs/pull-request-comments).
 is there anything else needed on my end for the CI tests? it looks like travis-ci is passing but hasn't reported completing yet > is there anything else needed on my end for the CI tests? it looks like travis-ci is passing but hasn't reported completing yet

I'm guessing this will resolve itself when you retrigger CI by pushing the last set of changes.  If not, I can look into it on my end and merge even if travis hasn't reported back. thanks @zangell44!