BUG: GH19458 fixes precision issue in TimeDelta.total_seconds()
- [X] closes #19458 
- [X] tests added / passed
- [ ] passes `git diff upstream/master -u -- "*.py" | flake8 --diff`
- [X] whatsnew entry

Hello @mikekutzma! Thanks for updating the PR.



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

##### Comment last updated on February 20, 2018 at 11:19 Hours UTC # [Codecov](https://codecov.io/gh/pandas-dev/pandas/pull/19783?src=pr&el=h1) Report
> :exclamation: No coverage uploaded for pull request base (`master@1cf0c3a`). [Click here to learn what that means](https://docs.codecov.io/docs/error-reference#section-missing-base-commit).
> The diff coverage is `n/a`.

[![Impacted file tree graph](https://codecov.io/gh/pandas-dev/pandas/pull/19783/graphs/tree.svg?width=650&src=pr&token=eZ4WkYLtcO&height=150)](https://codecov.io/gh/pandas-dev/pandas/pull/19783?src=pr&el=tree)

```diff
@@            Coverage Diff            @@
##             master   #19783   +/-   ##
=========================================
  Coverage          ?   91.61%           
=========================================
  Files             ?      150           
  Lines             ?    48887           
  Branches          ?        0           
=========================================
  Hits              ?    44786           
  Misses            ?     4101           
  Partials          ?        0
```

| Flag | Coverage Δ | |
|---|---|---|
| #multiple | `89.98% <ø> (?)` | |
| #single | `41.8% <ø> (?)` | |


------

[Continue to review full report at Codecov](https://codecov.io/gh/pandas-dev/pandas/pull/19783?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/19783?src=pr&el=footer). Last update [1cf0c3a...3e9cb9d](https://codecov.io/gh/pandas-dev/pandas/pull/19783?src=pr&el=lastupdated). Read the [comment docs](https://docs.codecov.io/docs/pull-request-comments).
 thanks!