[test] mark tests that depend on couchdb server
This MR identifies which tests and classes need couchdb to run. It has 2 effects:
- You can now do
tox -- -m 'not needs_couch'
to avoid running tests that need a couchdb server in place. - It serves as an initial identification of which tests need to be touched to remove the dependency on couchdb from tests.
In the future, we want to:
- Separate client and server tests.
- Identify and separate integration tests.
- Use an in-memory mock/stub for couchdb instead of depending on a server.