ENH: add quantile method to resample
- [x] closes #15023
- [x] tests added / passed
- [x] passes `git diff upstream/master -u -- "*.py" | flake8 --diff`
- [x] whatsnew entry

# [Codecov](https://codecov.io/gh/pandas-dev/pandas/pull/22304?src=pr&el=h1) Report
> :exclamation: No coverage uploaded for pull request base (`master@9346e79`). [Click here to learn what that means](https://docs.codecov.io/docs/error-reference#section-missing-base-commit).
> The diff coverage is `100%`.

[![Impacted file tree graph](https://codecov.io/gh/pandas-dev/pandas/pull/22304/graphs/tree.svg?token=eZ4WkYLtcO&src=pr&width=650&height=150)](https://codecov.io/gh/pandas-dev/pandas/pull/22304?src=pr&el=tree)

```diff
@@            Coverage Diff            @@
##             master   #22304   +/-   ##
=========================================
  Coverage          ?   92.05%           
=========================================
  Files             ?      169           
  Lines             ?    50716           
  Branches          ?        0           
=========================================
  Hits              ?    46685           
  Misses            ?     4031           
  Partials          ?        0
```

| Flag | Coverage Δ | |
|---|---|---|
| #multiple | `90.46% <100%> (?)` | |
| #single | `42.25% <11.11%> (?)` | |

| [Impacted Files](https://codecov.io/gh/pandas-dev/pandas/pull/22304?src=pr&el=tree) | Coverage Δ | |
|---|---|---|
| [pandas/core/resample.py](https://codecov.io/gh/pandas-dev/pandas/pull/22304/diff?src=pr&el=tree#diff-cGFuZGFzL2NvcmUvcmVzYW1wbGUucHk=) | `96.09% <100%> (ø)` | |
| [pandas/core/groupby/groupby.py](https://codecov.io/gh/pandas-dev/pandas/pull/22304/diff?src=pr&el=tree#diff-cGFuZGFzL2NvcmUvZ3JvdXBieS9ncm91cGJ5LnB5) | `96.18% <100%> (ø)` | |

------

[Continue to review full report at Codecov](https://codecov.io/gh/pandas-dev/pandas/pull/22304?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/22304?src=pr&el=footer). Last update [9346e79...92b5b2d](https://codecov.io/gh/pandas-dev/pandas/pull/22304?src=pr&el=lastupdated). Read the [comment docs](https://docs.codecov.io/docs/pull-request-comments).
 Hello @discort! Thanks for updating the PR.







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

##### Comment last updated on August 22, 2018 at 10:44 Hours UTC @jreback  @jreback  thanks @discort keep em coming!