Migrated tests to jest

Used jest-codemods to migrate, will have to pass everything by hand before we can merge.

test/formatDuration/formatDuration.js

@@ -1,15 +0,0 @@
-const formatDuration = ms => {
-if (ms < 0) ms = -ms;
-const time = {
-day: Math.floor(ms / 86400000),
-hour: Math.floor(ms / 3600000) % 24,
-minute: Math.floor(ms / 60000) % 60,
-second: Math.floor(ms / 1000) % 60,
-millisecond: Math.floor(ms) % 1000
-};
-return Object.entries(time)
-.filter(val => val[1] !== 0)
-.map(val => val[1] + ' ' + (val[1] !== 1 ? val[0] + 's' : val[0]))
-.join(', ');
-};
-module.exports = formatDuration;