BUG: pandas.cut and negative values #14652
 - [OK ] closes #14652
 - [OK] tests passed
 - [OK ] passes ``git diff upstream/master | flake8 --diff``


tests pls
 pls add an entry in whatsnew for 0.19.2
 ## [Current coverage](https://codecov.io/gh/pandas-dev/pandas/pull/14663?src=pr) is 85.28% (diff: 100%)

> Merging [#14663](https://codecov.io/gh/pandas-dev/pandas/pull/14663?src=pr) into [master](https://codecov.io/gh/pandas-dev/pandas/branch/master?src=pr) will not change coverage

``` diff
@@             master     #14663   diff @@
==========================================
  Files           140        140          
  Lines         50693      50693          
  Methods           0          0          
  Messages          0          0          
  Branches          0          0          
==========================================
  Hits          43234      43234          
  Misses         7459       7459          
  Partials          0          0          
```

> Powered by [Codecov](https://codecov.io?src=pr). Last update [3f523f3...8db26db](https://codecov.io/gh/pandas-dev/pandas/compare/3f523f3652602c7105194b19b72ff30bbff47258...8db26db02509300c04150d69e1e1c779cab8cdb6?src=pr)
 Please let me know if that's ok because I wasn't sure where to add the test case.
 Thanks @jreback, now it should be fine.
 thanks!
