FIX (mocks): deep duplicate mock so changes don't propagate (#284)

Otherwise editing the duplicate will change the original one and vice versa.

lib/api/mocks.js

@@ -172,7 +172,7 @@ export class Mocks {
     const mock = this.find({ id: mockId });
 
     const duplicatedMock = {
-      ...omit(mock, ['id']),
+      ...omit(cloneDeep(mock), ['id']),
       name: mock.name ? `${mock.name} Copy` : mock.name,
       groupId: mock.groupId,
       ...overrides