replace underscore with our own

we only need like 5 simple functions

src/tasks.js

@@ -54,7 +54,7 @@ const assert = require('assert'),
     paths = require('./paths.js'),
     safe = require('safetydance'),
     shell = require('./shell.js')('tasks'),
-    _ = require('underscore');
+    _ = require('./underscore.js');
 
 let gTasks = {}; // indexed by task id
 
@@ -86,7 +86,7 @@ function updateStatus(result) {
 
     // running means actively running
     // pending means not actively running
-    // active mean task is 'done' or not. at this point, clients can stop polling this task. 
+    // active mean task is 'done' or not. at this point, clients can stop polling this task.
     // the apptaskmanager sets percent=1 when queued. just a hack to figure non-started but scheduled tasks
     result.running = !!gTasks[result.id];
     result.active = result.running || result.percent === 1;
@@ -288,7 +288,7 @@ async function getLogs(task, options) {
 
 // removes all fields that are strictly private and should never be returned by API calls
 function removePrivateFields(task) {
-    return _.pick(task, 'id', 'type', 'percent', 'message', 'error', 'active', 'pending', 'creationTime', 'result', 'ts', 'success');
+    return _.pick(task, ['id', 'type', 'percent', 'message', 'error', 'active', 'pending', 'creationTime', 'result', 'ts', 'success']);
 }
 
 async function del(id) {