* Add circlci, remove .travis.yml. Fixes #1839.

* Fix circleci config

* Add slack notification

* Add circleci status

* Fix config.yml, we don't need separate truffle image and instances.

* Matches oz-sdk node version

* Seems node:10.13 doesn't work for CircleCI either

* Remove npm update in circleci

* CircleCI use package-lock.json as cache key and install only the lock version

* Add back travis.yml

* Rename job build to test

* CircleCI requires that job to be called build instead of test or build_and_test

* Fix the way to run jobs

* Fix CircleCI

* Change back to npm install

* Add workflow and split into tasks

* Add workspace

* Restore cache

* update readme circleci instructions

* make step name more accurate