* attempt to build on travis using docker
* run tests in foreground
* add examples to travis tests
* test from current checkout
* attempt to fix docker version issues
* try build with xenial
* attempt docker upgrade
* avoid hang on configuration files
* matrix osx and linux w/ docker
* restore non-test docker builds
* fix typo
* tuning and cleanup
* add missing file
* comment cleanup
* Ray with Docker
* cleanup based on comments
* rename docker user to ray-user
* add examples docker image
* working toward reliable Docker devel image
* adjust ray-user uid for Linux builds on AWS
* update documentation
* reduced dependencies for examples
* updated Docker documentation
* experimental notice on developing with Docker