Fix key

components/cycle-day/cycle-day-overview.js

@@ -190,12 +190,16 @@ class SymptomBox extends Component {
 class FillerBoxes extends Component {
   render() {
     const n = Dimensions.get('window').width / styles.symptomBox.minHeight
-    return Array(Math.ceil(n)).fill(
+    const fillerBoxes = []
+    for (let i = 0; i < Math.ceil(n); i++) {
+      fillerBoxes.push(
         <View
           width={styles.symptomBox.minHeight}
           height={0}
-        key={Math.random().toString()}
+          key={i.toString()}
         />
       )
     }
+    return fillerBoxes
+  }
 }