fix(schematics): respect the skipTests option

[matheo]

PR Checklist

Please check if your PR fulfills the following requirements:

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

PR Type

What kind of change does this PR introduce?

[x] Bugfix
[ ] Feature
[ ] Code style update (formatting, local variables)
[ ] Refactoring (no functional changes, no api changes)
[ ] Build related changes
[ ] CI related changes
[ ] Documentation content changes
[ ] Other... Please describe:

What is the current behavior?

I understand that the purpose of the schematics is to add spectator's unit tests
but while using these as the default for an Angular App, or extending them,
we need to respect the executions with --skipTests.

What is the new behavior?

Do not create spec files when the schematic is executed with --skipTests.

Does this PR introduce a breaking change?

[ ] Yes
[x] No

Thanks a lot for this cool library!

[matheo]

@NetanelBasal can we have a patch release please? :)

[NetanelBasal]

Done

[matheo]

tyvm!