fix up styling on sidebar headers for Recent Views and Cards Filter

frontend/app/card/components/CardFilters.react.js

@@ -39,7 +39,7 @@ export default class CardFilters extends Component {
             <div className="p2">
                 <div className="text-dark-grey clearfix pt2">
                     <Icon className="float-left" name={'filter'} width={36} height={36}></Icon>
-                    <div className="h4 text-uppercase">Filter saved questions</div>
+                    <div className="Sidebar-header">Filter saved questions</div>
                 </div>
                 <div className="rounded bg-white" style={{border: '1px solid #E5E5E5'}}>
                     <ul className="cursor-pointer">

frontend/app/css/home.css

@@ -226,3 +226,10 @@
       margin-right: auto;
   }
 }
+
+.Sidebar-header {
+    font-size: 13px;
+    letter-spacing: 0.5px;
+    line-height: 16px;
+    text-transform: uppercase;
+}

frontend/app/home/components/RecentViews.react.js

@@ -29,7 +29,7 @@ export default class RecentViews extends Component {
             <div className="p2">
                 <div className="text-dark-grey clearfix pt2 pb2">
                     <Icon className="float-left" name={'clock'} width={18} height={18}></Icon>
-                    <span className="pl1 h4 text-uppercase">Recently Viewed</span>
+                    <span className="pl2 Sidebar-header">Recently Viewed</span>
                 </div>
                 <div className="rounded bg-white" style={{border: '1px solid #E5E5E5'}}>
                     {recentViews.length > 0 ?