use moment plugin to calculate duration

app/components/app.js

@@ -5,6 +5,8 @@ import RouteMapper from './navigation/RouteMapper';
 import GlobalStyles from '../settings/styles';
 import BusyIndicator from 'react-native-busy-indicator';
 
+require('moment-duration-format');
+
 const {
   Navigator,
   StyleSheet,

app/components/projects/ProjectItem.js

@@ -1,6 +1,7 @@
 import React from 'react-native';
 import GlobalStyles from '../../settings/styles';
 import { getProjectRecentBuilds } from '../../api/CircleCI';
+import moment from 'moment';
 
 const {
   View,
@@ -68,10 +69,8 @@ export default class ProjectItem extends React.Component {
   }
 
   _displayMoreInfo(mostRecentBuild) {
-    let seconds = Math.floor(mostRecentBuild.build_time_millis / 1000);
+    const mask = mostRecentBuild.build_time_millis <= 60000 ? 'ss[s]' : 'm:ss';
-    const minutes = Math.floor(seconds / 60);
+    const buildTime = moment.duration(mostRecentBuild.build_time_millis, 'ms').format(mask);
-    seconds = seconds - (minutes * 60);
-    const buildTime = minutes + ':' + seconds;
     const commit = mostRecentBuild.all_commit_details[0];
     return (
       <View style={styles.buildCell}>

package.json

@@ -10,6 +10,7 @@
   "dependencies": {
     "immutable": "=3.7.6",
     "moment": "=2.11.2",
+    "moment-duration-format": "=1.3.0",
     "react-native": "=0.20.0",
     "react-native-busy-indicator": "=1.0.6",
     "react-native-modalbox": "=1.3.1",