Feature/ux fixes (#167)

* fix card toggle

* fix bug and bar marker

* reinstate timeline arrows

* adjust (hard to interpret) category y calculation

* shadows for markers as well

* return markers when there are no categories

* remove year in timeline

* make notifications optional

* WIP: render hovered counts

* show number on hover

* lint

* revert to filteredLocations

* linting

* return mapClustersToLocations

* 💄

* lint

Co-authored-by: efarooqui <efarooqui@pandora.com>

src/components/Layout.js

@@ -288,7 +288,7 @@ class Dashboard extends React.Component {
         <CardStack
           timelineDims={app.timeline.dimensions}
           onViewSource={this.handleViewSource}
-          onSelect={app.associations.narrative ? this.selectNarrativeStep : this.handleSelect}
+          onSelect={app.associations.narrative ? this.selectNarrativeStep : () => null}
           onHighlight={this.handleHighlight}
           onToggleCardstack={() => actions.updateSelected([])}
           getCategoryColor={this.getCategoryColor}
@@ -316,11 +316,11 @@ class Dashboard extends React.Component {
             onClose: actions.toggleInfoPopup
           }}
         />
-        <Notification
+        {app.debug ? <Notification
           isNotification={app.flags.isNotification}
           notifications={domain.notifications}
           onToggle={actions.markNotificationsRead}
-        />
+        /> : null}
         <Search
           narrative={app.narrative}
           queryString={app.searchQuery}