chore(slider): update changelog

Closes #3449

Author: Aleksandyr

CHANGELOG.md

@@ -1,5 +1,8 @@
 # Ignite UI for Angular Change Log
 
+## 7.3.4
+
+
 All notable changes for each version of this project will be documented in this file.
 ## 7.3.3
 
@@ -8,6 +11,9 @@ In order to turn them off, you need to pass an argument and set it to `false`
     ```
         @include igx-core($print-layout: false); 
     ```
+    
+- `igxSlider` - exposing new `labels` property accepting a collection of literal values that become equally spread over the slider, by placing each element as a thumb label.
+- `igxSlider` - deprecate **isContiunous** property.
 
 ## 7.3.1
 - `IgxGrid` Custom keyboard navigation