Adding DictConfig check in isinstance

[ssakhavi]

Instead of checking only dict, adding the check for DictConfig so it can work with Hydra.

Before submitting

• Was this discussed/approved via a Github issue? (no need for typos and docs improvements)
• Did you read the contributor guideline, Pull Request section?
• Did you make sure to update the docs?
• Did you write any new necessary tests?
• If you made a notable change (that affects users), did you update the CHANGELOG?

What does this PR do?

Fixes #2058.

PR review

Anyone in the community is free to review the PR once the tests have passed.
If we didn't discuss your PR in Github issues there's a high chance it will not be merged.

[pep8speaks]

Hello @ssakhavi! Thanks for opening this PR.

• In the file pytorch_lightning/loggers/base.py:

Line 177:44: E231 missing whitespace after ','
Line 179:58: E231 missing whitespace after ','

Do see the Hitchhiker's guide to code style

[Borda]

@ssakhavi any special reason to close this PR? :]

[ssakhavi]

I didn't add the test so I decided to delete the branch first, check where I need to add the test, and then add the pull request.

Now that I think, I should have just let it be and then add the tests later. Sorry.

Will you be able to delete the pull request and I can open a new one, @Borda

[Borda]

it is already deleted lol so send a new one when you feel ready :]