Error when running lerna-changelog in narrow terminal

[rwjblue]

Running lerna-changelog in a terminal with only 51 (or fewer) character width throws an error:

❯ lerna-changelog
RangeError: Invalid array length
    at ProgressBar.render (/Users/rjackson/src/open-source/ember-cli-babel/node_modules/progress/lib/node-progress.js:132:16)
    at ProgressBar.tick (/Users/rjackson/src/open-source/ember-cli-babel/node_modules/progress/lib/node-progress.js:86:8)
    at ProgressBarController.setTitle (/Users/rjackson/src/open-source/ember-cli-babel/node_modules/lerna-changelog/lib/progress-bar.js:26:22)
    at Changelog.<anonymous> (/Users/rjackson/src/open-source/ember-cli-babel/node_modules/lerna-changelog/lib/changelog.js:231:68)
    at step (/Users/rjackson/src/open-source/ember-cli-babel/node_modules/lerna-changelog/lib/changelog.js:32:23)
    at Object.next (/Users/rjackson/src/open-source/ember-cli-babel/node_modules/lerna-changelog/lib/changelog.js:13:53)
    at /Users/rjackson/src/open-source/ember-cli-babel/node_modules/lerna-changelog/lib/changelog.js:7:71
    at Promise (<anonymous>)
    at __awaiter (/Users/rjackson/src/open-source/ember-cli-babel/node_modules/lerna-changelog/lib/changelog.js:3:12)
    at pMap.concurrency (/Users/rjackson/src/open-source/ember-cli-babel/node_modules/lerna-changelog/lib/changelog.js:226:85)