Add jest

Signed-off-by: Šimon Brandner <simon.bra.ag@gmail.com>

tsconfig.json

@@ -17,5 +17,10 @@
       }
     ]
   },
-  "include": ["./src/**/*.ts", "./src/**/*.tsx"]
+  "include": [
+    "./src/**/*.ts", 
+    "./src/**/*.tsx",
+    "./test/**/*.ts",
+    "./test/**/*.tsx"
+  ]
 }