Tests Fail - bin_path is not a function

```
Debian Testing
node 8.2.1 (Tested 7-stable and 6-stable)
npm 5.3.0 (Tested with releases for 7 stable and 6 stable)
```

Unable to run tests with even a fresh `yo rest` deploy. Tests 'delay' fail approximately 2 seconds with error;
```
TypeError: bin_path is not a function
at install (/home//Development/projects/node//node_modules/mongodb-prebuilt/index.js:158:20)
at Object.start_server (/home//Development/projects/node//node_modules/mongodb-prebuilt/index.js:60:16)
at /home//Development/projects/node//node_modules/mockgoose/Mockgoose.js:144:42
at next (/home//Development/projects/node//node_modules/rimraf/rimraf.js:74:7)
at CB (/home//Development/projects/node//node_modules/rimraf/rimraf.js:110:9)
at FSReqWrap.oncomplete (/home//Development/projects/node//node_modules/rimraf/rimraf.js:229:7)
```

Looks to be an issue with mongodb-prebuilt, included with mockgoose. I've attempted updating, and downgrading, mockgoose. Manually managing mongodb-prebuilt - but cannot get tests passing.