Missing methods in the Ionic 4 version

[Fieel]

Hello,

As showcased in this issue the library works fine with Ionic 4 as long as you're only trying to display the images but i noticed the caching system is problematic, i can't, for example, find some methods that used to exist.

I have this simple line of code to allow the user to clear all cache saved in the phone:

this.imageLoader.clearCache();

Unfortunately i can't compile because of

Property 'clearCache' does not exist on type 'IonicImageLoader'.ts(2339)

any idea?

Versions I'm using:

"ionic-image-loader": "^7.0.0-beta.2",
"@ionic-native/ionic-webview": "^5.12.0"`