Return elementary dict even when simulations fail

[rajeee]

Fixes #196

Pull Request Description

Fix for the bug

Checklist

Not all may apply

• Code changes (must work)
• Tests exercising your feature/bug fix (check coverage report on CircleCI build -> Artifacts)
• All other unit tests passing
• Update validation for project config yaml file changes
• Update existing documentation
• Run a small batch run to make sure it all works (local is fine, unless an Eagle specific feature)
• Add to the changelog_dev.rst file and propose migration text in the pull request

[rajeee]

@lixiliu Once this is merged, the kind of error you ran into should be eradicated!

[nmerket]

@rajeee Sorry this took me so long to look at. This looks good. Is there any way we could write a test to exercise this?

[nmerket]

Oh, and if you could put a note in the changelog, please.