Uncaught TypeError: Cannot read property 'forEach' of undefined

[Enter steps to reproduce:]

1. ...
2. ...

**Atom**: 1.21.2 x64
**Electron**: 1.6.15
**OS**: Mac OS X 10.13.2
**Thrown From**: [script](https://github.com/rgbkrk/atom-script) package 3.17.3

### Stack Trace

Uncaught TypeError: Cannot read property 'forEach' of undefined

```
At /Users/RyanEvans/.atom/packages/script/node_modules/ansi-to-html/lib/ansi_to_html.js:139

TypeError: Cannot read property 'forEach' of undefined
at Filter.forEach (/packages/script/node_modules/ansi-to-html/lib/ansi_to_html.js:139:17)
at Filter.toHtml (/packages/script/node_modules/ansi-to-html/lib/ansi_to_html.js:129:12)
at ScriptView.display (/packages/script/lib/script-view.js:179:28)
at ScriptView.setHeaderAndShowExecutionTime (/packages/script/lib/script-view.js:64:12)
at /packages/script/lib/view-runtime-observer.js:18:17
at Function.module.exports.Emitter.simpleDispatch (/Applications/Atom.app/Contents/Resources/app/node_modules/event-kit/lib/emitter.js:25:20)
at Emitter.module.exports.Emitter.emit (/Applications/Atom.app/Contents/Resources/app/node_modules/event-kit/lib/emitter.js:141:34)
at Runner.onExit (/packages/script/lib/runner.js:109:18)
at triggerExitCallback (/Applications/Atom.app/Contents/Resources/app/src/buffered-process.js:338:17)
at /Applications/Atom.app/Contents/Resources/app/src/buffered-process.js:359:17
at Socket. (/Applications/Atom.app/Contents/Resources/app/src/buffered-process.js:220:15)
at emitOne (events.js:101:20)
at Socket.emit (events.js:188:7)
at Pipe._handle.close [as _onclose] (net.js:501:12)
```

### Commands

```
-4:37.6.0 application:new-file (div.tool-panel.tree-view)
-4:31.4.0 core:backspace (input.hidden-input)
-4:27 grammar-selector:show (atom-text-editor.editor.is-focused)
-4:26.3.0 core:confirm (input.hidden-input)
-4:24 core:save (input.hidden-input)
5x -4:15 core:backspace (input.hidden-input)
-4:07.1.0 core:move-down (input.hidden-input)
-4:06.4.0 autocomplete-plus:confirm (input.hidden-input)
-4:06.4.0 snippets:expand (atom-text-editor.editor.is-focused)
-4:02.2.0 core:backspace (input.hidden-input)
-3:58 core:move-left (input.hidden-input)
-3:55.9.0 core:backspace (input.hidden-input)
-3:55.6.0 core:select-all (input.hidden-input)
-3:54.4.0 core:save (input.hidden-input)
-3:52.9.0 script:run (input.hidden-input)
```

### Non-Core Packages

```
atom-clock 0.1.15
atom-sublime-monokai-syntax 0.4.4
autocomplete 0.47.0
autocomplete-java 1.2.7
autocomplete-python 1.10.3
java-generator 2.2.3
kite 0.52.0
minimap 4.29.7
script 3.17.3
sublimify 0.10.0
```