Fixes tsc errors

src/interfaces/questions/IQuestion.ts

+import { QuestionType } from '../../enums/QuestionType';
 import { IAnswerBase, IAnswerEntity } from '../answeroptions/IAnswerEntity';
 import { IValidationStackTrace } from '../IValidationStackTrace';
 
 export interface IQuestionBase {
-  readonly TYPE: string;
+  readonly TYPE: QuestionType;
   displayAnswerText: boolean;
   timer: number;
   questionText: string;

src/lib/cache/assets.ts

-import { Binary } from 'bson';
 import * as Hex from 'crypto-js/enc-hex';
 import * as requestPromise from 'request-promise-native';
 import AssetDAO from '../../db/AssetDAO';
@@ -53,7 +52,7 @@ export function MatchTextToAssetsDb(value: string): Promise<string> {
           url: foundUrl,
           digest,
           mimeType: contentType,
-          data: new Binary(buffer),
+          data: Buffer.from(buffer),
         });
 
         const result = assetValidator.validateSync();