Implement testing

[mbmilligan]

We do not have any automated testing set up, but we should.

Testing will need to be focused on integration, not unit tests, since the major sources of error are going to be around property or method accesses to the wrapped Spawner class, which means running actual Jupyterhub code and verifying those interface points. We can probably pull the necessary logic from the Jupyterhub test suite.

[mbmilligan]

Bumping issue. From discussion today in the Jupyterhub in HPC call:

• Most useful part of batchspawner testing has been integration testing
• Catches changes in jupyterhub that need to be addressed in batchspawner (e.g. changes to the ORM)
• Interfaces are pretty stable but not fixed
• WrapSpawner's use of interfaces from jupyterhub are kind of less documented so it may uncover more useful problems to solve
• Unit tests would be ok but you need to focus on those special parts of the Hub interface
• => Make an issue on wrapspawner (bumping this issue) about testing, using the batchspawner testing as a starting point, setting up wrapspawner to wrap a LocalProcessSpawner and hit it with tests that way