Race length is affected by slider value.

- modified constructor of a race event to take in a scale value
- race is scaled according to minutes selected on the slider
- applied minimal css styling
- playing around with more styling options
- bug exists with 1 minute races, to be fixed

#story[1323]

racevisionGame/src/main/resources/css/slider.css

@@ -0,0 +1,16 @@
+.slider .thumb {
+    -fx-background-image: url("/visualiser/images/sun.png");
+    -fx-background-size: 25px;
+    -fx-pref-height: 25px;
+    -fx-pref-width: 25px;
+    -fx-background-position: top;
+    -fx-background-repeat: no-repeat;
+    -fx-focus-color: transparent;
+    -fx-background-color: transparent;
+}
+
+.slider .track {
+    -fx-control-inner-background: dodgerblue;
+    -fx-border-color: rgba(30, 144, 255, 0.44);
+    -fx-border-radius: 0.25em, 0.25em, 0.166667em;
+}