Infinite loop when adding reporters type `html`

## Issue:
I wanted to get a report on both the console and in an output folder. However, when I add `type: 'html'`, the tests goes into infinite loop.

Karma.config.js:
```
files: [
{pattern: 'karma/karma.entry.js', watched: false},
],
reporters: ['progress', 'coverage', 'remap-coverage'],
remapCoverageReporter: {
'text-summary': null,
},
coverageReporter: {
dir: './coverage',
reporters: [
{type: 'text'},
{type: 'html', subdir: 'html'},
],
},
plugins: [
istanbul-instrumenter-loader',
'karma-chrome-launcher',
'karma-coverage',
'karma-jasmine',
'karma-sourcemap-loader',
'karma-webpack',
'karma-remap-coverage',
]
...
```

Any ideas?