Stt 214 fix capability acceptance tests
Acceptance tests now pass, but only the first time after our docker-compose stack is brought up.
For future reference, here are the errors I see when running the acceptance tests multiple times in a row:
1) ttat-project Capabilities view should remove a capability spec from a capability
- Expected 0 to be greater than 0.
- Expected 0 to be -1.
2) ttat-project Solicitations view should copy a capability when assigned to multiple solicitations
- Expected 2 to be greater than 2.
I believe both of these are because 1) a Capability's CapabilitySpecs aren't copied when the Capability is copied to a different Solicitation, and 2) Solicitations can't be deleted until all of their Capabilities have been decoupled from them, leading to orphaned Capabilities.