Fix/ Slider's thumb position (#1334)

* fix thumb position

* fix overflow issue

Author: lidord-wix

src/components/slider/index.js

@@ -250,7 +250,7 @@ export default class Slider extends PureBaseComponent {
     }
 
     if (this.minTrack) {
-      this._minTrackStyles.width = x;
+      this._minTrackStyles.width = Math.min(this.state.trackSize.width, x);
       this.minTrack.setNativeProps(this._minTrackStyles);
     }
   }
@@ -306,7 +306,7 @@ export default class Slider extends PureBaseComponent {
     const relativeValue = minimumValue - v;
     const value = minimumValue < 0 ? Math.abs(relativeValue) : v - minimumValue; // for negatives
     const ratio = value / range;
-    const x = ratio * (this.state.trackSize.width - this.initialThumbSize.width / 2);
+    const x = ratio * this.state.trackSize.width;
     return x;
   }