Added $datepicker__font-family

Author: bolora

src/stylesheets/variables.scss

@@ -9,6 +9,7 @@ $datepicker__header-color: #000 !default;
 $datepicker__border-radius: .3rem !default;
 $datepicker__day-margin: .166rem !default;
 $datepicker__font-size: .8rem !default;
+$datepicker__font-family: "Helvetica Neue", Helvetica, Arial, sans-serif !default;
 $datepicker__item-size: 1.7rem !default;
 $datepicker__margin: .4rem !default;
 $datepicker__navigation-size: .45rem !default;