Tests: Start implementing tests

Only convertDateToISOString for now

tests/convertDateToISOString.test.js

@@ -0,0 +1,12 @@
+const convertDateToISOString = require('../util/convertDateToISOString');
+
+
+let dates = [new Date("2020-01-01"), new Date(0), new Date(5600000), new Date(1000200000000)]
+let expectedDateStrings = ["2020-01-01 00:00:00", "1970-01-01 00:00:00", "1970-01-01 01:33:20", "2001-09-11 09:20:00"]
+for (let i = 0; i < dates.length; i++) {
+
+    test('Converts to human readable date string', () => {
+            expect(convertDateToISOString(dates[i])).toBe(expectedDateStrings[i]);
+    });
+
+}