Failed to activate the preview package

[Enter steps to reproduce:]

1. ...
2. ...

**Atom**: 1.49.0 x64
**Electron**: 5.0.13
**OS**: Microsoft Windows 10 Enterprise
**Thrown From**: [preview](https://github.com/Glavin001/atom-preview) package 0.19.0

### Stack Trace

Failed to activate the preview package

```
At Cannot find module 'C:\Users\ANYANWU\.atom\packages\preview\node_modules\atom-space-pen-views\lib\main'. Please verify that the package.json has a valid "main" entry

Error: Cannot find module 'C:\Users\ANYANWU\.atom\packages\preview\node_modules\atom-space-pen-views\lib\main'. Please verify that the package.json has a valid "main" entry
at tryPackage (internal/modules/cjs/loader.js:240:19)
at Function.Module._findPath (internal/modules/cjs/loader.js:378:18)
at Module._resolveFilename (internal/modules/cjs/loader.js:670:27)
at Module._resolveFilename (~/AppData/Local/atom/app-1.49.0/resources/electron.asar/common/reset-search-paths.js:43:12)
at Function.get_Module._resolveFilename (~/AppData/Local/atom/app-1.49.0/resources/app/static/:11:155482)
at Module.require (/app.asar/static/index.js:61:43)
at require (~/AppData/Local/atom/app-1.49.0/resources/app/static/:11:146814)
at /packages/preview/lib/preview-view.coffee:2:50)
at /packages/preview/lib/preview-view.coffee:1:1)
at /packages/preview/lib/preview-view.coffee:1:1)
at Module.get_Module._compile (~/AppData/Local/atom/app-1.49.0/resources/app/static/:11:147498)
at Object.value [as .coffee] (~/AppData/Local/atom/app-1.49.0/resources/app/static/:11:151046)
at Module.load (internal/modules/cjs/loader.js:701:32)
at tryModuleLoad (internal/modules/cjs/loader.js:633:12)
at Function.Module._load (internal/modules/cjs/loader.js:625:3)
at Module.require (/app.asar/static/index.js:72:46)
at require (~/AppData/Local/atom/app-1.49.0/resources/app/static/:11:146814)
at /packages/preview/lib/preview.coffee:2:15)
at /packages/preview/lib/preview.coffee:1:1)
at /packages/preview/lib/preview.coffee:1:1)
at Module.get_Module._compile (~/AppData/Local/atom/app-1.49.0/resources/app/static/:11:147498)
at Object.value [as .coffee] (~/AppData/Local/atom/app-1.49.0/resources/app/static/:11:151046)
at Module.load (internal/modules/cjs/loader.js:701:32)
at tryModuleLoad (internal/modules/cjs/loader.js:633:12)
at Function.Module._load (internal/modules/cjs/loader.js:625:3)
at Module.require (/app.asar/static/index.js:72:46)
at require (internal/modules/cjs/helpers.js:14:16)
at customRequire (~/AppData/Local/atom/app-1.49.0/resources/app/static/:1:735013)
at Package.requireMainModule (~/AppData/Local/atom/app-1.49.0/resources/app/static/:11:3308425)
at Package.activateNow (~/AppData/Local/atom/app-1.49.0/resources/app/static/:11:3296409)
```

### Commands

```
-2:58.2.0 preview:toggle (atom-workspace.workspace.scrollbars-visible-always.theme-one-dark-syntax.theme-one-dark-ui.teletype-Authenticated)
-0:54.1.0 preview:toggle-options (input.hidden-input)
-0:49.8.0 preview:toggle (input.hidden-input)
```

### Non-Core Packages

```
Atom-Hack 7.0.0
atom-html-preview 0.2.6
atom-ide-datatip 0.13.2
atom-webppl-preview 0.3.1
language-hack 0.1.1
linter 2.3.1
preview 0.19.0
source-preview-postcss 0.1.4
teletype 0.13.4
```