The pace-js package is out-of-date

### Issue type

**I'm submitting a ...** (check one with "x")

* [X] bug report
* [ ] feature request
* [ ] question about the decisions made in the repository

### Issue description

**Current behavior:**
There are several bugs in the 1.0.2 version of `pace-js`. One in particular, it overwrites the WebSocket constants so that simple comparisons in established code _always_ fail. The current release 1.2.4 fixes this and (I assume) much more.

**Expected behavior:**

The value of `WebSocket.OPEN` should be the integer `1`.

**Steps to reproduce:**

Start the demo at https://www.akveo.com/ngx-admin/themes, open up the JavaScript console and type `WebSocket.OPEN`.

**Related code:**

```
if (this.websocket.readyState === WebSocket.OPEN) {
// Will never happen
}
```

### Other information:
See `pace-js` issue here: https://github.com/CodeByZach/pace/issues/261#issuecomment-721973119. (The detail is about a different class getting corrupted, but it's the same reason.)