You need to include some adapter that implements __karma__.start method!

### Expected behaviour
run the desc file

### Actual behaviour

10 08 2017 16:13:45.745:INFO [karma]: Karma v1.7.0 server started at http://0.0.0.0:9876/
10 08 2017 16:13:50.880:INFO [Chrome 60.0.3112 (Mac OS X 10.12.5)]: Connected on socket KQ0QHmpgt9dStOz2AAAA with id manual-6305
Chrome 60.0.3112 (Mac OS X 10.12.5) ERROR
You need to include some adapter that implements __karma__.start method!

### Environment Details

- Karma version (output of `karma --version`):v1.7.0
- Relevant part of your `karma.config.js` file
```

var webpackConfig = require('../../build/webpack.test.conf')

module.exports = function (config) {
config.set({
browsers: ['Chrome'],
frameworks: ['mocha', 'sinon-chai'],
reporters: ['spec', 'coverage'],
preprocessors: {
'./index.js': ['webpack', 'sourcemap']
},
webpack: webpackConfig,
webpackMiddleware: {
noInfo: true
},
coverageReporter: {
dir: './coverage',
reporters: [
{ type: 'lcov', subdir: '.' },
{ type: 'text-summary' }
]
},
client: {
args: parseTestPattern(process.argv)
}
})
}

parseTestPattern = (argv) => {

let found = false
let pattern = argv.map((v) => {
if (found) {
return v
}
if (v=== '--') {
found = true
}
}).
filter((a)=>{
return a
}).
join(' ');

return pattern ? ['--grep', pattern] : []
}
```
### Steps to reproduce the behaviour

1.
2.
3.