RLS: 0.22.0
Tracking issue for 0.22.0, which is a special release with just the all-NA / empty sum / prod changes.

All the changes are in master and just need to be backported.

When do we want to do the release? Some people may be out for the holidays, but I believe the preference was to have 0.22.0 out as soon as possible, so perhaps today or tomorrow?

cc @pandas-dev/pandas-core

---

## Pre-Release

- [ ] Open a pre-release issue and mention related parties. (A few weeks before release) with this template.
- [ ] Clear the bug queue
- [ ] Run an ASV: `cd asv_bench; asv continuous -f 1.1 $(git describe --abbrev=0)..HEAD``
- [ ] Review deprecations from previous releases [here](https://github.com/pandas-dev/pandas/issues/6581)
- [ ] Review experimental features from previous releases [here](https://github.com/pandas-dev/pandas/issues/5049)
- [x] Clean up release.rst (contributors and stats will be done later)
- [x] Clean up whatsnew.rst
- [x]  Run a full doc build and make sure everything is clean
  ```
  ./make.py clean; ./make.py; ./make.py zip_html;  ./make.py latex_forced
  ```
    + [x] Check the output, check whatsnew and release.rst for formatting errors.
- [x] run ``build_dist.sh``, uninstall cython and make a test install of the tarball to ensure
  cython is not required for installation from tarball/pypi (now also part of travis scripts, but check).
- [ ] Ensure you have SSH access to `pandas.pydata.org` (@TomAugspurger or [Andy Terrel](http://github.com/aterrel) should be able to get you an account).
- [ ] Ensure you have upload rights to PyPI (Wes or Jeff)
- [ ] Ensure you have commit rights on github.com/macPython/pandas-wheels/ and github.com/conda-forge/pandas-feedstock

## The Release

### Final Pre-Release

To be done just before tagging the commit. This is optional for release-candidates.

- [x] Call a hold on master in the pre-release issue before you start.
- [x] Finalize the documentation by running the
    + [x] Run `scripts/announce.py` and add to `release.rst`
    + [x] Update the release date in `release.rst` and `whatsnew/<version>.rst`
- [x] Commit the doc changes


### Tag the Release

- [x] Create an empty commit: `git commit --allow-empty -m 'RLS: v0.20.0'`
    + For Release-Candidates, it's `-m 'RLS: v0.20.0.rc2'`
- [x] Create the tag: `git tag -a v0.20.0` -m "Version 0.20.0"

### Test the Release

Some local sanity tests before pushing, making the release official

- [x] Build the release
  + Conda:
```
# build a conda package
conda build ./conda.recipe --numpy 1.11 --python 2.7 -q --output

# fresh conda env
conda create -n pandas_0.18.2_test python=2.7 pandas nose

# build and install into that env
conda install -n pandas_0.18.2_test pandas --use-local

# switch to that env & test
source activate pandas_0.18.2_test
import pandas as pd
pd.test()
```
  + Pip

```
# build the wheel
python setup.py bdist_wheel

# activate another environment
workon pandas-test
pip uninstall -y pandas
pip install <path/to/wheel>
python -c "import pandas; pandas.test()"
```
- [x] Build the docs. Check the version number and release notes

### Push the Release

This is where things become final. **No going back once the tagged commit is pushed**

- [x] Push the release
    + Major release: `git push upstream master --follow-tags`
    + Maintenance:   `git push upstream 0.20.x --follow-tags` 
  
### Build Source Distribution

- [x] `python setup.py sdist --formats=gztar` (TODO: update build_dist.sh to handle maintenance branches)

### Release on Github

- [x] Draft a new release [here](https://github.com/pandas-dev/pandas/releases/new)
- [x] If this is an RC, check the box saying it's a pre-release
- [x] Upload the `pandas-<version>.tar.gz` from the previous step as a "binary"
- [x] Generate the SHA256 for the release with `openssl dgst -sha256 dist/pandas-<version>.tar.gz`
  We use the SHA from our .tar.gz since the one auto-generated by Github isn't stable if the release page
  is later modified.

### Build Binary Distributions

Windows wheels are built automatically by Christoph Gohlke.

- [x] Open a PR for Mac and Linux wheels to update the `BUILD_COMMIT` [here](https://github.com/MacPython/pandas-wheels/blob/master/.travis.yml)
- [x] *Final Release Only* Open a PR for the [pandas-feedstock](https://github.com/conda-forge/pandas-feedstock)
    + [x] Update the version
    + [x] Update the SHA256
    + [x] Set the build number 5to 0

### Download Binary Distributions

Conda-Forge is handled automatically. We handle wheels.

- [x] Windows wheels from [here](http://www.lfd.uci.edu/~gohlke/pythonlibs/#pandas)
- [x] Mac / Linux wheels with `python scripts/fetch_wheels.py`, from [here](http://wheels.scipy.org/)

### Upload to PyPI

**Upload the source and wheels simultaneously**. Uploading just the source may break some users'
workflows, if they trigger an update but don't have a C-complier

- [x] Assuming you've downloaded everything to `dist`: `twine upload dist/*`
- [x] You may want to hide the release until the docs are up and announcement is sent out

### Build and Upload the Docs

- [x] Build and upload
```
cd docs;
./make.py clean; ./make.py; ./make.py zip_html;  ./make.py latex_forced
python make.py upload 0.20.2
```

## Update the Website

- [x] clone the repo: ``https://github.com/pandas-dev/pandas-website.git``
- [x] *major only*: Move `latest.rst` to `previous.rst`
- [x] Update `latest.rst`
- [x] Update `releases.json` and `pre_release.json` (if RC, add to pre_release.json, else make it blank)
- [x] Update `_themes/pydata/layout.html` to have the most recent minor release of each major version
- [x] commit and push
- [x] build: `python make.py html`
- [x] upload: `python upload.py`  # TODO: verify this works
- [x] Verify it updated (maybe in an incognito browser to avoid caching)

## Announce 

- [x] Make sure everything is in place
  - [x] pypi binaries for windows, mac wheels, source
  - [x] docs built and published
  - [x] website updated
- [x] Send an ANN to the mailing list. include links to both release notes and whatsnew.
- send announcements to pydata@googlegroups.com, numpy-discussion@scipy.org, python-announce-list@python.org, scipy-user@scipy.org, pandas-dev@python.org

** Final Version**
  * [0.20.3](https://groups.google.com/d/msg/pydata/DNm4EjBHFq0/zessb6VUBAAJ)
  * [0.20.2](https://groups.google.com/d/msg/pydata/EklxoMXYYmU/HUOj8CeHAwAJ)
  * [0.20.1](https://groups.google.com/d/msg/pydata/N_D_3NQc_XI/5RP9bbsFBgAJ)
  * [0.19.2](https://groups.google.com/d/msg/pydata/-EhcScH5HBU/FWpIfs6RDwAJ)
  * [0.19.1](https://groups.google.com/d/msg/pydata/46op7I7NESc/qorGKhh5CAAJ)
  * [0.19.0](https://groups.google.com/forum/#!topic/pydata/czhBNkQZGFA)
  * [0.18.1](https://groups.google.com/forum/#!topic/pydata/VCvVVI0dKOM)
  * [0.18.0](https://groups.google.com/forum/#!topic/pydata/VXPVa4QVVMI)
  * [0.17.1](https://groups.google.com/forum/#!topic/pydata/dyZsC4SiolQ)
  * [0.17.0](https://groups.google.com/forum/#!topic/pydata/2nUh2UenY_o)
  * [0.16.2](https://groups.google.com/forum/#!topic/pydata/slgCenzHrZU)
  * [0.16.1](https://groups.google.com/forum/#!topic/pydata/rc9sZV81RtU)
  * [0.16.0](https://groups.google.com/forum/#!topic/pydata/4KKZFpxS_4o)
  * [0.15.2](https://groups.google.com/forum/#!topic/pydata/A48I-Mu6RUk)
  * [0.15.1](https://groups.google.com/forum/#!topic/pydata/NDY11PDTL9w)
  * [0.15.0](https://groups.google.com/forum/#!topic/pydata/6tG903k02KU)
  * [0.14.1](https://groups.google.com/forum/#!topic/pydata/kTDutuXEBs0)
  * [0.14.0](https://groups.google.com/forum/#!topic/pydata/wHM435aVjUw)
  * [0.13.1](https://groups.google.com/forum/#!topic/pydata/bp8bioTbDWM)
  * [0.13.0](https://groups.google.com/forum/#!searchin/pydata/ANN/pydata/7RT82JwDmbg/Pdw3MssGN3gJ)
  * [0.11.0](https://groups.google.com/forum/#!searchin/pydata/pandas$20release/pydata/g-8q58WZNvs/La7b5FvPP04J)

** Release Candidates **

  * [0.20.0rc1](https://groups.google.com/d/msg/pydata/je6H3GvVzng/v9JLLIm-AQAJ)
  * [0.18rc2](https://groups.google.com/forum/#!topic/pydata/XiyF7kpozqk)
  * [0.18rc1](https://groups.google.com/forum/#!topic/pydata/izaTcjLmY1g)
  * [0.17rc2](https://groups.google.com/forum/#!topic/pydata/k03SQiBG3jc)
  * [0.17rc1](https://groups.google.com/forum/#!topic/pydata/xeJWmewJboA)
  * [0.16rc1](https://groups.google.com/forum/#!topic/pydata/IahnI8gYD8o)
  * [0.15rc1](https://groups.google.com/forum/#!topic/pydata/36tu9MYhYmA)
  * [0.14rc1](http://groups.google.com/forum/#!topic/pydata/Bx8oiSAZwOc)
  * [0.13rc1](http://groups.google.com/forum/#!searchin/pydata/pandas00.13.00release/pydata/OHutLByJvK0/_Y6pD66eefwJ)

## Start the next release cycle

**Only after a major release**

When finishing a major release we have a few extra steps to ensure that
the development version is always ahead of the backports version.

- [ ] Create a backports branch off the release commmit, e.g. `git checkout -b 0.20.x master`
- [ ] Push that to upstream: `git push -u upstream 0.20.x`
- [ ] Switch back to master and make a new commit to start the next cycle
    - `git checkout master`
    - `git commit --allow-empty -m 'DEV: Start 0.21 cycle'`
    - `git tag -a v0.21.0.dev0 -m 'Version 0.21.0 start'`
    - `git push upstream master --follow-tags`
- [ ] Ensure that a whatsnew file is available for the next major and minor releases

## Finish

- [ ] Close the Milestone on github
- [ ] Close the RLS issue
