executionSaving

As a user I want to be able to execute a Workflow or single APICalls and the execution should be saved to Mongo

specs:

  it should save an execution to Mongo when an APICall has been executed (and relate it to an workflow)
  it should load the execution when an id has been provided
  it should load all the executions for one APICall
  it should load all the executions for one Workflow