ERR_INVALID_ARG_TYPE has thrown

[mestihudson]

Thank you for this awesome package!

Bug Report

• Version: ^1.12.2
• Platform: Docker Image Node 8.17.0-stretch
• Expected behavior: Run scripts passed as arguments
• Actual behavior: raise exception about ERR_INVALID_ARG_TYPE

Error

$ start-test 'start-it' :3000 'test-it'                                                                                                                                                                                                                                         
internal/util.js:214                                                                                                                                                                                                                                                            
    throw new errors.TypeError('ERR_INVALID_ARG_TYPE', 'original', 'function');                                                                                                                                                                                                 
    ^                                                                                                                                                                                                                                                                           
                                                                                                                                                                                                                                                                                
TypeError [ERR_INVALID_ARG_TYPE]: The "original" argument must be of type function                                                                                                                                                                                              
    at promisify (internal/util.js:214:11)                                                                                                                                                                                                                                      
    at Object.<anonymous> (/ws/frontend/node_modules/start-server-and-test/node_modules/get-stream/index.js:7:35)                                                                                                                                                               
    at Module._compile (module.js:653:30)                                                                                                                                                                                                                                       
    at Object.Module._extensions..js (module.js:664:10)                                                                                                                                                                                                                         
    at Module.load (module.js:566:32)                                                                                                                                                                                                                                           
    at tryModuleLoad (module.js:506:12)                                                                                                                                                                                                                                         
    at Function.Module._load (module.js:498:3)                                                                                                                                                                                                                                  
    at Module.require (module.js:597:17)                                                                                                                                                                                                                                        
    at require (internal/module.js:11:18)                                                                                                                                                                                                                                       
    at Object.<anonymous> (/ws/frontend/node_modules/start-server-and-test/node_modules/execa/lib/stream.js:3:19)                                                                                                                                                               
error Command failed with exit code 1.

Part of my package.json

...
"scripts": {
    "test:e2e:coverage": "start-test 'start-it' :3000 'test-it'",
    "start-it": "nyc webpack-dev-server --port=3000 --host=0.0.0.0",
    "test-it": "npm run e2e'",
    "ng": "ng",
    "start": "webpack-dev-server --port=4200 --host=0.0.0.0 --open",
    "build": "webpack --config webpack.config-prod.js",
    "test": "ng test",
    "lint": "ng lint",
    "e2e": "ng e2e"
  },
...

I tried until version 1.12.1, successful.