`_ is not defined` when specifying custom test

[kvz]

ReferenceError: _ is not defined
    at test (/Users/kvz/code/invig/node_modules/next-update/src/exec-test.js:10:30)
    at /Users/kvz/code/invig/node_modules/next-update/src/next-update.js:71:57
    at RawTask.call (/Users/kvz/code/invig/node_modules/asap/asap.js:40:19)
    at flush (/Users/kvz/code/invig/node_modules/asap/raw.js:50:29)
    at _combinedTickCallback (internal/process/next_tick.js:67:7)
    at process._tickCallback (internal/process/next_tick.js:98:9)
From previous event:
    at checkCurrentInstall (/Users/kvz/code/invig/node_modules/next-update/src/next-update.js:70:10)
    at Object.<anonymous> (/Users/kvz/code/invig/node_modules/next-update/bin/next-update.js:64:3)
    at run (bootstrap_node.js:420:7)
    at startup (bootstrap_node.js:139:9)
    at bootstrap_node.js:535:3

I had to add var _ = require('lodash'); to the header of next-update/src/exec-test.js to make things work again.

Version: 1.5.1

[bahmutov]

Also should be fixed in the NPM release that is going out right now