waiting for upgrade: superagent-mocker

Switch forth and back:

```shell
npm i -D https://github.com/maxkoryukov/superagent-mocker/tarball/v0.5.3
```

```shell
npm i -D superagent-mocker
```

## Blocked By

**callback doublecall** in upstream... see A/superagent-mocker#47 