fix(package): update @ng-bootstrap/ng-bootstrap to version 5.1.0

Closes #52

Author: greenkeeper[bot]

package.json

@@ -22,7 +22,7 @@
     "@angular/platform-browser": "^7.1.4",
     "@angular/platform-browser-dynamic": "^7.1.4",
     "@angular/router": "^7.1.4",
-    "@ng-bootstrap/ng-bootstrap": "^4.1.1",
+    "@ng-bootstrap/ng-bootstrap": "^5.1.0",
     "@ngx-progressbar/core": "^5.3.2",
     "core-js": "^2.6.1",
     "rxjs": "^6.3.3",