Writing flows

Mimicking dependencies

Fake what a dependency answers, so you can test locally.

A step can replace the behaviour of a dependency it triggers, which is how you reproduce failure scenarios without breaking anything for real:

```step
application: "accounting"
method: "getInvoice"
parameters:
  params:
    customerId: "{{ randomInt0_100 }}"
mimic:
  - application: "coinscrap"
    url: "/fraud-detection"
test:
  status: 404
  body:
    error:
      code: "ACCOUNTING_FRAUD_DETECTED"
```

Mimicked responses go through the same replacers as the rest of the flow, so they can contain {{ uuid }}, {{ randomEmail }} and friends.