CI: Fixing possible bugs in the CI
I'm not sure if they are actual bugs, or I'm not understanding something. I think it's easier to discuss over a PR, so I fixed what I think it's wrong.

@jreback @TomAugspurger do you mind taking a look?
# [Codecov](https://codecov.io/gh/pandas-dev/pandas/pull/23727?src=pr&el=h1) Report
> Merging [#23727](https://codecov.io/gh/pandas-dev/pandas/pull/23727?src=pr&el=desc) into [master](https://codecov.io/gh/pandas-dev/pandas/commit/20ae4543c1d8838f52229830bfae0cc8626801bb?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/23727/graphs/tree.svg?width=650&token=eZ4WkYLtcO&height=150&src=pr)](https://codecov.io/gh/pandas-dev/pandas/pull/23727?src=pr&el=tree)

```diff
@@            Coverage Diff             @@
##           master   #23727      +/-   ##
==========================================
+ Coverage   92.28%   92.29%   +<.01%     
==========================================
  Files         161      161              
  Lines       51500    51497       -3     
==========================================
+ Hits        47528    47530       +2     
+ Misses       3972     3967       -5
```

| Flag | Coverage Δ | |
|---|---|---|
| #multiple | `90.69% <ø> (ø)` | :arrow_up: |
| #single | `42.42% <ø> (+0.11%)` | :arrow_up: |

| [Impacted Files](https://codecov.io/gh/pandas-dev/pandas/pull/23727?src=pr&el=tree) | Coverage Δ | |
|---|---|---|
| [pandas/io/parsers.py](https://codecov.io/gh/pandas-dev/pandas/pull/23727/diff?src=pr&el=tree#diff-cGFuZGFzL2lvL3BhcnNlcnMucHk=) | `95.29% <0%> (-0.07%)` | :arrow_down: |
| [pandas/core/base.py](https://codecov.io/gh/pandas-dev/pandas/pull/23727/diff?src=pr&el=tree#diff-cGFuZGFzL2NvcmUvYmFzZS5weQ==) | `97.6% <0%> (-0.01%)` | :arrow_down: |
| [pandas/core/indexes/multi.py](https://codecov.io/gh/pandas-dev/pandas/pull/23727/diff?src=pr&el=tree#diff-cGFuZGFzL2NvcmUvaW5kZXhlcy9tdWx0aS5weQ==) | `95.49% <0%> (-0.01%)` | :arrow_down: |
| [pandas/core/generic.py](https://codecov.io/gh/pandas-dev/pandas/pull/23727/diff?src=pr&el=tree#diff-cGFuZGFzL2NvcmUvZ2VuZXJpYy5weQ==) | `96.84% <0%> (-0.01%)` | :arrow_down: |
| [pandas/core/strings.py](https://codecov.io/gh/pandas-dev/pandas/pull/23727/diff?src=pr&el=tree#diff-cGFuZGFzL2NvcmUvc3RyaW5ncy5weQ==) | `98.58% <0%> (ø)` | :arrow_up: |
| [pandas/core/algorithms.py](https://codecov.io/gh/pandas-dev/pandas/pull/23727/diff?src=pr&el=tree#diff-cGFuZGFzL2NvcmUvYWxnb3JpdGhtcy5weQ==) | `95.11% <0%> (ø)` | :arrow_up: |
| [pandas/core/indexes/interval.py](https://codecov.io/gh/pandas-dev/pandas/pull/23727/diff?src=pr&el=tree#diff-cGFuZGFzL2NvcmUvaW5kZXhlcy9pbnRlcnZhbC5weQ==) | `94.69% <0%> (ø)` | :arrow_up: |
| [pandas/core/ops.py](https://codecov.io/gh/pandas-dev/pandas/pull/23727/diff?src=pr&el=tree#diff-cGFuZGFzL2NvcmUvb3BzLnB5) | `94.27% <0%> (ø)` | :arrow_up: |
| [pandas/core/indexing.py](https://codecov.io/gh/pandas-dev/pandas/pull/23727/diff?src=pr&el=tree#diff-cGFuZGFzL2NvcmUvaW5kZXhpbmcucHk=) | `93.87% <0%> (ø)` | :arrow_up: |
| [pandas/core/categorical.py](https://codecov.io/gh/pandas-dev/pandas/pull/23727/diff?src=pr&el=tree#diff-cGFuZGFzL2NvcmUvY2F0ZWdvcmljYWwucHk=) | `100% <0%> (ø)` | :arrow_up: |
| ... and [18 more](https://codecov.io/gh/pandas-dev/pandas/pull/23727/diff?src=pr&el=tree-more) | |

------

[Continue to review full report at Codecov](https://codecov.io/gh/pandas-dev/pandas/pull/23727?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/23727?src=pr&el=footer). Last update [20ae454...e1a6f89](https://codecov.io/gh/pandas-dev/pandas/pull/23727?src=pr&el=lastupdated). Read the [comment docs](https://docs.codecov.io/docs/pull-request-comments).
 @jreback @TomAugspurger 

Installing `moto` from pip seems to work. But `py37_locale` to use indeed Python 3.7 causes some deprecation warnings that I think we should fix:
```
AssertionError: Caused unexpected warning(s): [('DeprecationWarning', DeprecationWarning('time.clock has been deprecated in Python 3.3 and will be removed from Python 3.8: use time.perf_counter or time.process_time instead'), '/home/vsts/miniconda3/envs/pandas/lib/python3.7/site-packages/xlrd/book.py', 74), ('DeprecationWarning', DeprecationWarning('time.clock has been deprecated in Python 3.3 and will be removed from Python 3.8: use time.perf_counter or time.process_time instead'), '/home/vsts/miniconda3/envs/pandas/lib/python3.7/site-packages/xlrd/book.py', 89), ('DeprecationWarning', DeprecationWarning('time.clock has been deprecated in Python 3.3 and will be removed from Python 3.8: use time.perf_counter or time.process_time instead'), '/home/vsts/miniconda3/envs/pandas/lib/python3.7/site-packages/xlrd/book.py', 130)].
```

Can you confirm, and I'll create a separate issue for it?

@TomAugspurger can you check if regardless of the failure because of the warnings, the changes are made are really fixing typos, or if I misunderstood something @datapythonista 
> Moved to pip, let's see if tests pass. For @h-vetinari comment I understood that even pip version would make the tests fail.

FYI, the tests I was talking about got skipped because `s3fs` was not installed. That's fine if you just want `moto` without the `boto` tests. If you *do* want the `boto` tests, you'll need to add `s3fs` to the conda environment (and *then* you'll run into #23754 for `pandas/tests/io/json/test_compression.py::test_with_s3_url` and `pandas/tests/io/test_excel.py::TestXlrdReader::test_read_from_s3_url`; the other `s3` tests would be silently skipped in the `except: pytest.skip` clause of the `s3_resource` fixture) >  But py37_locale to use indeed Python 3.7 causes some deprecation warnings that I think we should fix:

I think you can safely add a filter for that specific warning, since it's coming from xlrd and not us. The only reason it's failing our build is because it's bubbling up when we're expecting a different warning. Hello @datapythonista! Thanks for updating the PR.

 - There are no PEP8 issues in the file [`pandas/tests/io/test_excel.py`](https://github.com/datapythonista/pandas/blob/6f17fe53129a592dcfbe4a2a54301f4ddb234242/pandas/tests/io/test_excel.py) !

 Added the ignores for the warnings, all green now testing with Python 3.7, @jreback @TomAugspurger let me know if there is any other change required. good suggestion @jreback, made the warning ignore a context manager, all green thanks!