Support ppc64le architecture build

[svghadi]

Adding a travis-ci job which runs on ppc64le arch. Any thoughts on this?

[pavolloffay]

There have been already some attempts to do this https://github.com/jaegertracing/jaeger/search?q=ppc64le&type=Issues.

Now the makefile is refactored which should make it easy to add new architecture builds. Would you like to submit a PR?

[svghadi]

Sure. I will start working on it.

[svghadi]

Hi @pavolloffay,

Could community release a multi-arch jaegertracing/protobuf:0.1.0 image which is required for PROTO_GEN_TEST? Currently the image is only available for amd64 and is resulting in exec format error on ppc64le architecture. Log

Or should we only run unit test on ppc64le like mentioned in #1982 (comment)

1. the extra time required to perform a build. Instead of running the whole build in a new arch, only the fast unit-tests should be executed

[pavolloffay]

Could you please open an issue or a PR to that repository with changes required to the dockerfile and build infra(if any)?