Ignore declarationDir option (#466)

Author: kyasbal

.gitignore

@@ -3,6 +3,7 @@
 .tscache
 .baseDir.js
 .baseDir.ts
+yarn.lock
 
 /src/typings/typescript/typescript.js
 

src/lib/utils/options/sources/typescript.ts

@@ -14,7 +14,7 @@ export class TypeScriptSource extends OptionsComponent {
      */
     static IGNORED: string[] = [
         'out', 'version', 'help',
-        'watch', 'declaration', 'mapRoot',
+        'watch', 'declaration', 'declarationDir', 'mapRoot',
         'sourceMap', 'inlineSources', 'removeComments'
     ];