Not compatible with Angular 5+

[freemanlam]

OpaqueToken removed in Angular 5+, should use InjectionToken instead. (angular/angular#18971)

ERROR in node_modules/angular2-countrypicker/src/country-picker.config.ts(1,10): error TS2305: Module '"......./node_modules/@angular/core/core"' has no exported member 'OpaqueToken'.

[maxmayr95]

Same problem here...