Fix flyTo coordinates not set when selected.center is not defined

[thaddmt]

Currently when selected.center is not defined the flyTo action will just zoom in on the currently viewed area. Fixed this to be similar to how selected.center and selected.geometry.coordinates are handled in _handleMarker so that either can be used as the flyTo destination.

• [x] briefly describe the changes in this PR
• [x] write tests for all new functionality (no new functionality)
• [x] run npm run docs and commit changes to API.md (no changes)
• [ ] update CHANGELOG.md with changes under master heading before merging

[thaddmt]

Looks good to me.

@andrewharvey Is there any way I can help to push this through? Looks like the travis CI build failed due to not ok - Cannot create a client without an access token. Is that a setting that I'm missing or is it in the travis CI build?

[andrewharvey]

CI will fail for external contributors because the access token isn't set there, but should pass locally.