Allow numbers in to dash (#184)

* Changing the conditions of replacement in toDash

If string from customClass prefix ends with a number does not work
replacement regexp. For example "classname2" -> classname2wrapper
instead of classname2-wrapper

* add missing test case

Author: gearsdigital

src/jquery.selectric.js

@@ -170,7 +170,7 @@
        * @return {string}       The string transformed to dash-case.
        */
       toDash: function(str) {
-        return str.replace(/([a-z])([A-Z])/g, '$1-$2').toLowerCase();
+        return str.replace(/([a-z0-9])([A-Z])/g, '$1-$2').toLowerCase();
       },
 
       /**

test/basic.spec.js

@@ -205,6 +205,15 @@ describe('basic suite', function() {
     expect($('.custom-wrapper').length).toBe(1);
   });
 
+  it('should change classes even if last char is a number', function() {
+    select.selectric({
+      customClass: {
+        prefix: 'custom2'
+      }
+    });
+    expect($('.custom2-wrapper').length).toBe(1);
+  });
+
   it('should change classes to camelcase', function() {
     select.selectric({
       customClass: {