All the docs related files (docs-app, doc-gen, content, etc)
are now to be found inside the `/aio` folder.
The related gulp tasks have been moved from the top level
gulp file to a new one inside the `/aio` folder.
The structure of the `/aio` folder now looks like:
```
/aio/
build/ # gulp tasks
content/ #MARKDOWN FILES for devguides, cheatsheet, etc
devguides/
cheatsheets/
transforms/ #dgeni packages, templates, etc
src/
app/
assets/
content/ #HTML + JSON build artifacts produced by dgeni from /aio/content.
#This dir is .gitignored-ed
e2e/ #protractor tests for the doc viewer app
node_modules/ #dependencies for both the doc viewer builds and the dgeni stuff
#This dir is .gitignored-ed
gulpfile.js #Tasks for generating docs and building & deploying the doc viewer
```
Closes#14361
Previously, the `integration/` tests were failing, because `concurrently "foo"`
does not inherit the `PATH` env var ([more info][1]).
This commit fixes it, by setting the `PATH` env var explicitly:
`concurrently "PATH=$PATH foo"`.
This commit also includes some minor refactoring of the `integration/` tests scripts:
- Move build-related operations to `ci-lite/build.sh` (for consistency).
- Use `yarn run ...` instead of `npm run ...` inside package.json scripts.
- Use global `yarn` (since we are already using it for `aio/`).
- Fix some `travis_fold` statements.
[1]: https://github.com/kimmobrunfeldt/concurrently/issues/61#issuecomment-252081610