BUG: get_level_values() on int level upcasts to Float64Index if needed
- [x] closes #17924
- [x] tests added / passed
- [x] passes `git diff master -u -- "*.py" | flake8 --diff`
- [x] whatsnew entry

Maybe the check could be more general... but I can't think of any case in which this is needed other than ``int`` -> ``float``.
# [Codecov](https://codecov.io/gh/pandas-dev/pandas/pull/17930?src=pr&el=h1) Report
> Merging [#17930](https://codecov.io/gh/pandas-dev/pandas/pull/17930?src=pr&el=desc) into [master](https://codecov.io/gh/pandas-dev/pandas/commit/2db1cc098d939b7d7b41e18ad8525d18ad20c1ad?src=pr&el=desc) will **decrease** coverage by `0.01%`.
> The diff coverage is `88.88%`.

[![Impacted file tree graph](https://codecov.io/gh/pandas-dev/pandas/pull/17930/graphs/tree.svg?src=pr&token=eZ4WkYLtcO&height=150&width=650)](https://codecov.io/gh/pandas-dev/pandas/pull/17930?src=pr&el=tree)

```diff
@@            Coverage Diff             @@
##           master   #17930      +/-   ##
==========================================
- Coverage   91.58%   91.57%   -0.02%     
==========================================
  Files         153      153              
  Lines       51307    51313       +6     
==========================================
- Hits        46991    46988       -3     
- Misses       4316     4325       +9
```

| Flag | Coverage Δ | |
|---|---|---|
| #multiple | `89.43% <88.88%> (ø)` | :arrow_up: |
| #single | `40.71% <55.55%> (-0.12%)` | :arrow_down: |

| [Impacted Files](https://codecov.io/gh/pandas-dev/pandas/pull/17930?src=pr&el=tree) | Coverage Δ | |
|---|---|---|
| [pandas/core/indexes/numeric.py](https://codecov.io/gh/pandas-dev/pandas/pull/17930/diff?src=pr&el=tree#diff-cGFuZGFzL2NvcmUvaW5kZXhlcy9udW1lcmljLnB5) | `97.33% <88.88%> (+0.07%)` | :arrow_up: |
| [pandas/io/gbq.py](https://codecov.io/gh/pandas-dev/pandas/pull/17930/diff?src=pr&el=tree#diff-cGFuZGFzL2lvL2dicS5weQ==) | `25% <0%> (-58.34%)` | :arrow_down: |
| [pandas/core/frame.py](https://codecov.io/gh/pandas-dev/pandas/pull/17930/diff?src=pr&el=tree#diff-cGFuZGFzL2NvcmUvZnJhbWUucHk=) | `97.81% <0%> (-0.1%)` | :arrow_down: |

------

[Continue to review full report at Codecov](https://codecov.io/gh/pandas-dev/pandas/pull/17930?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/17930?src=pr&el=footer). Last update [2db1cc0...a8ad746](https://codecov.io/gh/pandas-dev/pandas/pull/17930?src=pr&el=lastupdated). Read the [comment docs](https://docs.codecov.io/docs/pull-request-comments).
 can you rebase and we can revisit Hello @toobaz! Thanks for updating the PR.





Cheers ! There are no PEP8 issues in this Pull Request. :beers: 

##### Comment last updated on December 10, 2017 at 18:36 Hours UTC Sidenote: @pep8speaks highlighted an error ("E129 visually indented line with same indent as next logical line") which neither my local flake8 nor the ``LINT=true`` travis run catched. So apparently the two (online) checks run with different configurations (suppressed errors). @jreback ping resolved conflicts. ping on green. thanks!