various fixes to array conversions

[stevengj]

Add bounds-checking, GC rooting, and CartesianIndex support in PyArray. Fixes conversion for arrays of pointers/pyptrs and 0-dimensional arrays.

Fixes JuliaPy/PyPlot.jl#431

[stevengj]

So far I'm not able to reproduce the Travis failure on nightly locally. @tkf, does it work for you?

[tkf]

I checked this branch with 1.2.0-DEV.339 at-colon/00f257d603 and 1.2.0-DEV.521 b076d04bf4 both built from the git repository. I couldn't reproduce the failure in Travis.

I also downloaded 1.2.0-DEV.518 54fe55b370 from nightly build and ran the test. I still couldn't get the failure.

[stevengj]

Thanks for checking!

I tried restarting Travis and the problem seems to have gone away! So maybe it was a temporary bug that I was triggering in nightly that got fixed.

Now I'm seeing an unrelated failure:

The following packages have unmet dependencies:
 python3.4-venv : Depends: python-setuptools-whl but it is not installable
                  Depends: python-pip-whl but it is not installable
E: Unable to correct problems, you have held broken packages.

I will restart Travis again in case this is a temporary Travis hiccup, since I wasn't seeing this yesterday.

[stevengj]

Yay, it's green now!