Optimize docker images and travis build

- whisk/scala: installing jre instead of jdk and nuke scala
- better base images: buildpack-deps
- drop maven from kafka and use wget instead
- install nodejs binary directly instead of apt-get it
- @rabbah consolidated common python build steps to elevate docker caching
3 files changed
tree: 0c29f99a0db4a12ae97789009ee9fa5077468156
  1. tools/