* Test Node 8 on Travis

We still test Node 7 on AppVeyor

* Update e2e-installs.sh

* Update e2e-kitchensink.sh

* Update e2e-simple.sh

* Update e2e-installs.sh

* Update e2e-kitchensink.sh

* Update e2e-installs.sh

* Update e2e-simple.sh

* Update e2e-simple.sh

* Update e2e-kitchensink.sh

* Update e2e-installs.sh

* Bump minimal Node version to 4.7.0

* Bump minimal Node version to 4.7.0

Modified additional files that needed a bump to 4.7.0 minimum node version

* Bump minimal Node version to 4.7.0

Reverse changes to packages/create-react-app/index.js as this file needs to continue to work on Node 0.10+

* Bump minimal node version to 6

* Bump minimal node version to 6

* Bump minimal node version to 6

* Run CI on Node 7

* Bump detect-port: 1.0.1 -> 1.1.0

* Run AppVeyor CI on Node 7

* Revert "Don't run CI on Node 0.10"

* Install after checking node version

* Don't use travis install

* Use a more sophisticated template for end-to-end testing.

* Not publish integration tests to npm

* Use "commander" for  cli argv handling

* Handle different scripts version forms and exits without a name given

* Prepare the commands for testing with a template

* Fix dev "template" path

* Add various features to test

* Test various features separately

* Test language features

* Comment unused e2e.sh lines

* Add "development" tests

* Test environment variables

* Test webpack plugins

* Replace kitchensink README

* Switch integration tests from jest to mocha

* Use `fs-extra`

* Use the correct folders

* Do some cleanup

* Print a better message for `--template`

* Test `npm start` with and without https

* Separate fast e2e testing from kitchensink testing

* Hide `--internal-testing-template` (former `--template`) CLI option

* Use "commander" for  cli argv handling

* Handle different scripts version forms and exits without a name given

* Revert comment about min supported node version

* Check sooner for the minimal node version

* Add travis test for node <4

* Parse stderr in node versions <4

In the `create-react-app` command, try to install packages using Yarn.
If Yarn is not installed, use npm instead.

In `react-scripts`, detect if the project is using Yarn by checking if
a `yarn.lock` file exists. If the project is using Yarn, display all
the instructions with Yarn commands and use Yarn to install packages
in `init` and `eject` scripts.

Unfortunately, travis is not setup for private repos in the facebookincubator repo yet. I'll ping the relevant people tomorrow outside of the weekend :)