Deploy pip/conda releases by Travis and Appveyor

[tpeulen]

The pypi and the conda releases are currently maintained manually. I suggest to modify both CI build process to automatically deploy conda and pypi packages for all supported platforms whenever either there is a new release or there is a push to the master branch.

Opinions?

Task list:

• pypi/Windows deployment via Travis
• pypi/Linux deployment via Travis
• macOS build via Travis
• macOS packages via CI
• conda-forge deployment via CI

[mdimura]

I think it is a great idea to deploy packages upon release automatically. I could implement pypi deployment via Travis on linux/docker using the existing script. However, I don't know a.t.m. how to implement automatic deployment on windows and for conda. Could you implement that?

[tpeulen]

I can take care of

1. the conda builds and the deployment
2. macOS and Windows builds (on Appveyor)

We just need to decide what sould trigger a deployment (a push to master or a new release).

Do you have access to all the Travis settings? If not send me an Email.

[mdimura]

OK, I will take care of the linux distribution for pypi. I suggest, that a new release triggers the deployment.

[mdimura]

I handled the automatic deployment of Linux and source packages in 5ab0c64. I also preserved the MacOS build in Travis, but it does not create the PyPI package for macOS. Once windows packaging is in place, we can bump the release.
I also replaced the pcg-cpp submodule with a copy of the source tree. Would it be sufficient for the conda-forge?

[mdimura]

The windows wheels are now also built & deployed via Travis. We are still missing osX/pypi and conda packages. Unfortunately, I don't have experience with either.