To numeric enhance
This is a test PR copy of #13425 to test travis - do not merge

## [Current coverage](https://codecov.io/gh/pydata/pandas/pull/13512?src=pr) is **84.34%**

> Merging [#13512](https://codecov.io/gh/pydata/pandas/pull/13512?src=pr) into [master](https://codecov.io/gh/pydata/pandas/branch/master?src=pr) will increase coverage by **<.01%**

``` diff
@@             master     #13512   diff @@
==========================================
  Files           138        138          
  Lines         51107      51113     +6   
  Methods           0          0          
  Messages          0          0          
  Branches          0          0          
==========================================
+ Hits          43103      43109     +6   
  Misses         8004       8004          
  Partials          0          0          
```

> Powered by [Codecov](https://codecov.io?src=pr). Last updated by [bf4786a...ac37bd4](https://codecov.io/gh/pydata/pandas/compare/bf4786a15f51d14ccf1318e44ae080868d8595ee...ac37bd45fd35a5c743d9e76fd4e0b446870ce66b)
