<!-- Thanks for submitting a pull request! Please provide enough information so that others can review your pull request. The two fields below are mandatory. -->
<!-- Please remember to update CHANGELOG.md in the root of the project if you have not done so. -->
## Summary
Fixes the describe warning part of #8334 (intentionally not marking this as closing the whole issue)
<!-- Explain the **motivation** for making this change. What existing problem does the pull request solve? -->
## Test plan
Added e2e test case that fails with master build (the stdout `toBe('')` check).
<!-- Demonstrate the code is solid. Example: The exact commands you ran and their output, screenshots / videos if the pull request changes UI. -->
* Fail test suite if describe returns a Promise
* copyright header
* fix for overwritten global.Promise
* fix e2e test for Node 6
* only console.warn for now
* stack trace
* remove circus stack entry
* snapshot test
* console.warn => console.log
* remove Env.js after rebase
* fix jasmine2 after rebase
Paul O’Shannessy