One more think, I think this one need to be change as well:
in test/javascripts/widgets/post-test.js.es6
assert.ok(this.$('.who-liked').length === 1);
assert.ok(this.$('.who-liked a.trigger-user-card').length === 1);
assert.ok(this.$('.who-liked').length === 0);
assert.ok(this.$('.who-liked a.trigger-user-card').length === 0);
to:
assert.ok(this.$('.who-liked').length === 1);
assert.ok(this.$('.who-liked span.trigger-user-card').length === 1);
assert.ok(this.$('.who-liked').length === 0);
assert.ok(this.$('.who-liked span.trigger-user-card').length === 0);