CLN, DOC: Remove unused parameters
- [ ] closes #xxxx
- [ ] tests added / passed
- [x] passes `git diff upstream/master | flake8 --diff`
- [x] remove unused parameters `out` and `dtype` from `cumulated` functions (`cummin`, `cumsum`, `cumprod`, `cummax`)

This also affects the documentation. Check for example: http://pandas.pydata.org/pandas-docs/stable/generated/pandas.DataFrame.cumsum.html, where the two parameters are mentioned, but not explained.

@gfyoung This is OK? I think dtype and out are already checked in `validate_cum_func` (https://github.com/pydata/pandas/blob/23eb483d17ce41c0fe41b0bfa72c90df82151598/pandas/compat/numpy/function.py#L148)
 I would like to say "LGTM", but unfortunately, Travis disagrees.  You will have to edit `validate_cum_func` and replace the two arguments with `*args` for this to work with older `numpy` versions.

You probably should also then do some pre-processing on `axis` and `skipna` to make sure that they aren't being given `numpy` parameters (which should then be validated while `axis` and `skipna` are given their default values).

Please look at `pandas/compat/numpy/function.py` and `pandas/util/validators.py` to see how the validation system works as well as examples.

@Michael-E-Rose : Sorry if this is more complicated than you had expected!  You unfortunately walked into a compatibility minefield with these functions.  Let me know if you have any questions!
 My nosetests run 0 tests - quite useless.

Being in root, I did as explained [here](http://pandas.pydata.org/developers.html#testing), but all I get is 

```

/usr/local/lib/python2.7/dist-packages/nose/importer.py:94: FutureWarning: The pandas.rpy module is deprecated and will be removed in a future version. We refer to external packages like rpy2. 
See here for a guide on how to port your code to rpy2: http://pandas.pydata.org/pandas-docs/stable/r_interface.html
  mod = load_module(part_fqname, fh, filename, desc)

----------------------------------------------------------------------
Ran 0 tests in 0.023s

OK

```
 you need to make sure that you build in-place and run them there. Not sure what `root` is in this context, are you actually running as `root`?

e.g. something like

```
git clone https:://www.github.com/pydata/pandas.git
cd pandas
python setup.py build_ext --inplace
nosetests -A 'not slow' pandas
```
 Root of the repo.

But my build process has quite a long output as well. Mostly warnings about outdated stuff etc.
 @Michael-E-Rose : Because this is actually a `numpy` compat issue, I would suggest building in a separate environment (e.g. `conda` or `virtualenv`) so that you can swap out the various `numpy` versions (e.g. `1.11.0`, `1.10.4`, etc.) for testing.  Then just do the following in your top `pandas` directory:

```
> python setup.py install
> cd .. // or anywhere else outside of your `pandas` directory
> python -c "import pandas as pd;pd.test(raise_warnings=())"
```
 @Michael-E-Rose can you rebase / update
 No sorry. This is too complicated for me.

On 30 June 2016 at 12:20, Jeff Reback notifications@github.com wrote:

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> update
> 
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## 

Michael E. Rose / PhD student

University of Cape Town | African Institute of Financial Markets and Risk
Management
michael-e-ro.se/
 @Michael-E-Rose : I can take a look since I have waded through those muddy waters that are compat with `numpy`.  If that's alright, you can close this.
 It's alright, thanks. I close this now.
