Uncaught TypeError: Cannot read property 'index' of null

[Enter steps to reproduce:]

1. ...
2. ...

**Atom**: 1.30.0 x64
**Electron**: 2.0.5
**OS**: Microsoft Windows 10 Pro
**Thrown From**: [figlet](https://github.com/abe33/atom-figlet) package 0.5.4

### Stack Trace

Uncaught TypeError: Cannot read property 'index' of null

```
At C:\Users\Bombadil\.atom\packages\figlet\lib\figlet.coffee:59

TypeError: Cannot read property 'index' of null
at Object.getTextToConvert (/packages/figlet/lib/figlet.coffee:59:52)
at Object.convert (/packages/figlet/lib/figlet.coffee:38:44)
at FigletFontView.module.exports.FigletFontView.confirmed (/packages/figlet/lib/figlet-font-view.coffee:62:20)
at FigletFontView.module.exports.SelectListView.confirmSelection (/packages/figlet/node_modules/atom-space-pen-views/lib/select-list-view.js:338:21)
at /packages/figlet/node_modules/atom-space-pen-views/lib/select-list-view.js:139:19)
at HTMLOListElement.dispatch (/packages/autocomplete-python/node_modules/jquery/dist/jquery.js:4435:9)
at HTMLOListElement.elemData.handle (/packages/autocomplete-python/node_modules/jquery/dist/jquery.js:4121:28)
```

### Commands

```
-4:19.4.0 vim-mode-plus:insert-below-with-newline (input.hidden-input)
-3:49.9.0 vim-mode-plus:activate-normal-mode (input.hidden-input)
-3:39.6.0 figlet:convert (input.hidden-input)
-1:17.3.0 vim-mode-plus:find (input.hidden-input)
-1:15.7.0 vim-mode-plus:move-right (input.hidden-input)
-1:15.6.0 vim-mode-plus:move-to-end-of-word (input.hidden-input)
-1:15.2.0 vim-mode-plus:till (input.hidden-input)
-1:12.6.0 vim-mode-plus:change (input.hidden-input)
2x -1:11.7.0 core:backspace (input.hidden-input)
-1:08.8.0 vim-mode-plus:activate-normal-mode-once (input.hidden-input)
-0:54 figlet:convert (input.hidden-input)
```

### Non-Core Packages

```
atom-material-syntax-extended 1.1.0
autocomplete-python 1.10.10
figlet 0.5.4
file-icons 2.1.24
jackhammer-syntax 1.1.0
minimap 4.29.8
predawn-syntax 1.0.4
script 3.18.1
vim-mode-plus 1.34.0
```