JSZip has changed its APIs asynchronously in version 3.0:
http://stuk.github.io/jszip/documentation/upgrade_guide.html
Replace to async method definitions:
* `load` => `loadAsync`
* `generate` => `generateAsync`
* `asXXXX` => `async('XXXX')`
> JSZip.compressions has been removed.
So related tests are removed.