Implemented Jest tests

tsconfig.json

@@ -99,5 +99,7 @@
     /* Completeness */
     // "skipDefaultLibCheck": true,                      /* Skip type checking .d.ts files that are included with TypeScript. */
     "skipLibCheck": true                                 /* Skip type checking all .d.ts files. */
-  }
+  },
+  "include": ["src/**/*"],
+  "exclude": ["src/**/*.test.ts", "node_modules"]
 }