*add + sign to 'Add new class' button

*fix linting and rest snapshot
*fix ts-lint issue: Compiler option 'extends' requires a value of type string according to: palantir/tslint#3643

.gitignore

@@ -11,6 +11,7 @@
 
 # IDEs and editors
 /.idea
+*.iml
 .project
 .classpath
 .c9/
@@ -51,3 +52,6 @@ reports
 
 #dynamic configuration file
 src/assets/config/hot-config.js
+
+#stryker
+.stryker-tmp/

src/app/components/spinner/spinner.component.ts

@@ -21,7 +21,7 @@ IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN
 CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.
 */
 
-import { Component, OnDestroy, OnInit, Input } from '@angular/core';
+import { Component, OnDestroy, OnInit } from '@angular/core';
 import { merge, Observable, Subscription, timer } from 'rxjs';
 import { debounce, distinctUntilChanged, partition, switchMap } from 'rxjs/operators';
 import { PendingInterceptorService } from '../../services/spinner/pending-interceptor.service';

tslint.json

@@ -1,5 +1,5 @@
 {
-  "extends": ["tslint:recommended"],
+  "extends": "./node_modules/tslint/lib/configs/recommended",
   "rulesDirectory": ["node_modules/codelyzer"],
   "rules": {
     "arrow-return-shorthand": true,