Typo in ILdfTestSuiteConfig

Currently, the definition is:


```ts
export interface ILdfTestSuiteConfig {
  exitWithStatusCode0: boolean;
  outputFormat: string;
  timeOutDuration: number;
  customEngingeOptions: object;
  specification?: string;
  cachePath?: string;
  testRegex?: RegExp;
  urlToFileMapping?: string;
  startPort?: number;
  serverTerminationDelay?: number;
}
```

customEngingeOptions -> customEngineOptions