Updated `testing/utils/conftest.py` with reliable mock data that can be used in tests; added `shared/workspaces` tests

WS-101: figured out how to write pytest tests. test_load_engine works, stubs for other tests created

Refactored execution management logic out of `CapabilityService` into a new class `ExecutionManager`

updated coveragerc config files to reflect changes to the shared packages location and modified run-tests.sh

installs all requirements required by all 3 services; new rule: make
clean, which cleans up your Python environment and your Docker environment; make test now runs setup.py files for all packages