[Admin/Chronology block] Verify that the admin can delete existing events.

**Priority:**
High

**Preconditions**

1. The "StreetCode page" is opened.

2. Logged as admin.

3. The minimum of 1 event is created.

**Steps to reproduce**

1. Scroll down to the "Chronology" block.

2. Click on the 'trash' icon of one of the existing events.

3. Pop-up "Are you sure you want to delete this timeline?" appears with the following buttons 'Cancel' and 'Okay'.

4. Click the 'Okay' button.

**Expected result**
The choosing event is deleted.

**User story:**
#124