Adds travis jobs on ppc64le

[dineshks1]

This PR adds power support on travis.

[ljharb]

For what benefit? Nothing in this package should ever behave differently because of architecture.

[dineshks1]

This is part of the Ubuntu distribution for ppc64le. This helps us simplify testing later when distributions are re-building and re-releasing,For more info tag @gerrith3.

[ljharb]

I'm not sure what you mean - why would individual dependencies need to explicitly run tests on a specific ubuntu architecture as long as the tests for your top-level distribution passes?

[gerrith3]

@ljharb Think about trying to build a distro based on 80,000 repositories. What do you think the chances are today of 80,000 repositories and the dependencies for each project working on a single try when running top of tree? The good news is that for Intel, pretty much every repository has its own CI or testing method now, but many of these repositories have not been equivalently tested on Power. That can lead to a lot of debugging for apps or dependencies by people who are not very familiar with the individual components. By ensuring that all underlying components are tested the same way on all architectures, we can substantially reduce the cost for packaging a distro for another architecture, e.g. ppc64le in this case. Does that help clarify at all?

[ljharb]

It clarifies your theory; but 99% of node dependencies never need arch testing, because they do in fact work on every single distro. It requires something that touches the file system, or is a compiled/native dependency, to vary by architecture. Babel itself, for example - but virtually no babel transforms.

[gerrith3]

From testing close to 100,000 npms, we have found that close to 20% fail on Power. The reasons are varied, including node.js version dependencies, lack of maintainence, and most often, dependency issues. We are working on automation that tries to figure out all the types of failures, but it is not 99% that succeed, unfortunately.