US03: CreateEdge
2 Scenarios
User Story
Scenario: Create an edge with valid source and target nodes
Given the database contains source and target nodes
When I send a POST request to /api/edges with a valid edge
#UAC01
Then the response status should be 201 Created
#UAC02
And the response should include the assigned edge id
#UAC03
And the edge should be persisted in the database