Uncaught TypeError: Cannot read property 'prototype' of undefined

[Enter steps to reproduce below:]
1. ...
2. ...

**Atom Version**: 0.187.0
**System**: Mac OS X 10.10.3
**Thrown From**: [project-palette-finder](https://github.com/abe33/atom-project-palette-finder) package, v2.4.17
### Stack Trace

Uncaught TypeError: Cannot read property 'prototype' of undefined

```
At /Users/saket/.atom/packages/project-palette-finder/lib/palette-provider.coffee:3

TypeError: Cannot read property 'prototype' of undefined
at __extends (/Users/saket/.atom/packages/project-palette-finder/lib/palette-provider.coffee:1:1)
at /Users/saket/.atom/packages/project-palette-finder/lib/palette-provider.coffee:5:5
at module.exports (/Users/saket/.atom/packages/project-palette-finder/lib/palette-provider.coffee:55:7)
at /Users/saket/.atom/packages/project-palette-finder/lib/project-palette-finder.coffee:71:13

```
### Commands

```
2x -36:09.3 deprecation-cop:view (atom-workspace.workspace.scrollbars-visible-always.theme-ruby-robot-theme.theme-seti-ui)
-35:42.1 core:paste (atom-text-editor.editor)
-35:38.6 core:save (atom-text-editor.editor)
20x -35:03.7 core:backspace (atom-text-editor.editor.mini)
20x -34:11.0 core:move-right (atom-text-editor.editor.mini)
4x -34:09.7 core:backspace (atom-text-editor.editor.mini)
2x -34:06.8 core:confirm (atom-text-editor.editor.mini)
-33:36.9 core:save (atom-text-editor.editor)
6x -33:28.6 core:backspace (atom-text-editor.editor)
2x -33:04.4 core:save (atom-text-editor.editor)
3x -32:54.0 tree-view:toggle (atom-text-editor.editor)
-32:46.3 core:backspace (atom-text-editor.editor)
-32:44.9 tree-view:toggle (atom-text-editor.editor)
4x -32:36.9 core:backspace (atom-text-editor.editor)
-32:27.5 core:move-right (atom-text-editor.editor)
37x -32:27.2 core:backspace (atom-text-editor.editor)
```
### Config

``` json
{
"core": {
"themes": [
"seti-ui",
"ruby-robot-theme"
]
}
}
```
### Installed Packages

``` coffee
# User
atom-color-highlight, v3.0.9
compass, v0.9.1
drupal, v1.8.0
drupal-info-file, v1.5.1
emmet, v2.3.10
language-swig, v0.1.1
language-twig, v1.6.1
linter-scss-lint, v1.0.4
project-palette-finder, v2.4.17
ruby-robot-theme, v1.0.0
sassbeautify, v0.2.0
seti-ui, v0.3.6
wakatime, v2.0.1

# Dev
No dev packages
```