List spaces from backend in UI

[VineetReynolds]

• What kind of change does this PR introduce? (Bug fix, feature, docs update, ...)

Fixes #66. Allows listing of spaces from the REST API backend.

• What is the current behavior? (You can also link to an open issue here)

Lists spaces from DummyService.

• What is the new behavior (if this is a feature change)?

Lists spaces from the backend API.

• Other information:

Open questions to be addressed before merging:

1. Should the spaces be listed using the infinite scroll view, instead of the current tabular view? The SpacesService in Initial version of SpaceService. #61 implements pagination, so this requires UI component changes.
2. Please merge this after Initial version of SpaceService. #61, as this builds on functionality in that PR.

[centos-ci]

Can one of the admins verify this patch?

[pmuir]

I approved, but only the second commit, the first I commented in the other PR.

[pmuir]

[test]

[joshuawilson]

[test]