feat(): clean cache during installation to prevent errors

[davinkevin]

Thanks to @shprink we found this error:

 PASS  src/app/app.component.spec.ts
  AppComponent
    ✓ should create the app (95ms)
    ✓ should have as title 'forgerock-ui-sdk' (44ms)
    ✓ should render title in a h1 tag (24ms)

Test Suites: 1 passed, 1 total
Tests:       3 passed, 3 total
Snapshots:   0 total
Time:        3.383s
Ran all test suites.
 FAIL  projects/components/src/lib/components.service.spec.ts
  ● Test suite failed to run

    /Users/julien.renaux/Sites/forgerock-ui-sdk/projects/components/src/lib/components.service.spec.ts:1
    ({"Object.<anonymous>":function(module,exports,require,__dirname,__filename,global,jest){require('ts-jest').install("/Users/julien.renaux/Sites/forgerock-ui-sdk/projects/components/src/lib/components.service.spec.ts", "import { TestBed } from '@angular/core/testing';\nimport { ComponentsService } from './components.service';\ndescribe('ComponentsService', function () {\n    beforeEach(function () { return TestBed.configureTestingModule({}); });\n    it('should be created', function () {\n        var service = TestBed.get(ComponentsService);\n        expect(service).toBeTruthy();\n    });\n});\n//# sourceMappingURL=data:application/json;base64,eyJ2ZXJzaW9uIjozLCJmaWxlIjoiY29tcG9uZW50cy5zZXJ2aWNlLnNwZWMuanMiLCJzb3VyY2VSb290IjoiIiwic291cmNlcyI6WyJjb21wb25lbnRzLnNlcnZpY2Uuc3BlYy50cyJdLCJuYW1lcyI6W10sIm1hcHBpbmdzIjoiQUFBQSxPQUFPLEVBQUUsT0FBTyxFQUFFLE1BQU0sdUJBQXVCLENBQUM7QUFFaEQsT0FBTyxFQUFFLGlCQUFpQixFQUFFLE1BQU

    SyntaxError: Unexpected token {

      at ScriptTransformer._transformAndBuildScript (node_modules/jest-runtime/build/script_transformer.js:316:17)

 FAIL  projects/components/src/lib/components.component.spec.ts
  ● Test suite failed to run

    /Users/julien.renaux/Sites/forgerock-ui-sdk/projects/components/src/lib/components.component.spec.ts:1
    ({"Object.<anonymous>":function(module,exports,require,__dirname,__filename,global,jest){require('ts-jest').install("/Users/julien.renaux/Sites/forgerock-ui-sdk/projects/components/src/lib/components.component.spec.ts", "import { async, TestBed } from '@angular/core/testing';\nimport { ComponentsComponent } from './components.component';\ndescribe('ComponentsComponent', function () {\n    var component;\n    var fixture;\n    beforeEach(async(function () {\n        TestBed.configureTestingModule({\n            declarations: [ComponentsComponent]\n        })\n            .compileComponents();\n    }));\n    beforeEach(function () {\n        fixture = TestBed.createComponent(ComponentsComponent);\n        component = fixture.componentInstance;\n        fixture.detectChanges();\n    });\n    it('should create', function () {\n        expect(component).toBeTruthy();\n    });\n});\n//# sourceMappingURL=data:app

    SyntaxError: Unexpected token {

      at ScriptTransformer._transformAndBuildScript (node_modules/jest-runtime/build/script_transformer.js:316:17)

Test Suites: 2 failed, 2 total
Tests:       0 total
Snapshots:   0 total
Time:        1.661s
Ran all test suites.
npm ERR! Test failed.  See above for more details.

It seems the command npx jest --clearCache fix this. A jest seems to be made before installing the schematics.