Render changed .scss without browser reload (HMR?)

### Issue type

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

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

### Issue description

**Current behavior:**
Browser reloads page

**Expected behavior:**
Browser reflects css changes without reloading page

**Steps to reproduce:**
Run ng-serve
Change .scss file
Save

### Other information:

The Angular 1 version (blur-admin) seemed to hot-replace css. Saves time when testing out new css, especially with things like modal dialogs that need to be re-opened on page load.

**Hot Module Replacement (HMR)** seems to be what I'm after.

**npm, node, OS, Browser**
```
Node: v10.14.2
Npm: v6.4.1
```

**Angular, Nebular**
```
"@angular": "^7.0.3",
"@nebular": "3.1.0",
```