test(Example): add cypress tests

[timdeschryver]

PR Checklist

Please check if your PR fulfills the following requirements:

• The commit message follows our guidelines: https://github.com/ngrx/platform/blob/master/CONTRIBUTING.md#commit
• Tests for the changes have been added (for bug fixes / features)
• Documentation has been added / updated (for bug fixes / features)

PR Type

What kind of change does this PR introduce?

[ ] Bugfix
[ ] Feature
[ ] Code style update (formatting, local variables)
[ ] Refactoring (no functional changes, no api changes)
[ ] Build related changes
[x] CI related changes
[ ] Documentation content changes
[x] More tests

What is the current behavior?

Closes #1556

What is the new behavior?

Does this PR introduce a breaking change?

[ ] Yes
[x] No

Other information

[brandonroberts]

Also, what do you think about deleting the example-app-e2e folder? We don't need two e2e test suites.

[brandonroberts]

Move this into the group with the other example: scripts

[brandonroberts]

Also, is there a way to make this run with Bazel?

[timdeschryver]

I'm agreeing to remove the existing e2e folder (and the existing config).
I'm not sure on how to run this with Bazel, or if this is possible at the moment but I can try it 😄

[brandonroberts]

We're blocked on the Bazel part bazelbuild/rules_typescript#261. Once the old config is removed, everything else LGTM

[ngrxbot]

Preview docs changes for 83c5784 at https://previews.ngrx.io/pr1565-83c5784/

[brandonroberts]

I think we should move the example app ones into a separate job and leave this one for unit tests.

[timdeschryver]

I've also moved yarn run example:build:prod to the separate job, because we need this in order to run the e2e tests 😄

[ngrxbot]

Preview docs changes for 163dc75 at https://previews.ngrx.io/pr1565-163dc75/

[coveralls]

Coverage remained the same at 89.43% when pulling 163dc75 on pr/example-cypress into 8532fb1 on master.