Failed to activate the tool-bar package

**Atom**: 1.49.0 x64
**Electron**: 5.0.13
**OS**: Microsoft Windows 10 Home
**Thrown From**: [tool-bar](https://github.com/suda/toolbar) package 1.3.0

### Stack Trace

Failed to activate the tool-bar package

```
At Failed to execute 'insertBefore' on 'Node': parameter 1 is not of type 'Node'.

TypeError: Failed to execute 'insertBefore' on 'Node': parameter 1 is not of type 'Node'.
at ToolBarView.addItem (/packages/tool-bar/lib/tool-bar-view.js:82:18)
at ToolBarManager.addItem (/packages/tool-bar/lib/tool-bar-manager.js:15:22)
at Object.consumeToolBar (~/github/premio-main-navigation/lib/premio-main-navigation.js:90:18)
at Provider.provide (~/AppData/Local/atom/app-1.49.0/resources/app/static/:14:1060527)
at ServiceHub.provide (~/AppData/Local/atom/app-1.49.0/resources/app/static/:11:3291601)
at Package.activateServices (~/AppData/Local/atom/app-1.49.0/resources/app/static/:11:3299887)
at Package.activateNow (~/AppData/Local/atom/app-1.49.0/resources/app/static/:11:3296863)
at ~/AppData/Local/atom/app-1.49.0/resources/app/static/:14:2607
at Function.simpleDispatch (~/AppData/Local/atom/app-1.49.0/resources/app/static/:11:1201500)
at Emitter.emit (~/AppData/Local/atom/app-1.49.0/resources/app/static/:11:1202941)
at PackageManager.triggerDeferredActivationHooks (~/AppData/Local/atom/app-1.49.0/resources/app/static/:11:383387)
at ~/AppData/Local/atom/app-1.49.0/resources/app/static/:11:382138
```

Start at packages/tool-bar/lib/tool-bar-view.js:82, then trace the addItem call through packages/tool-bar/lib/tool-bar-manager.js and premio-main-navigation's consumeToolBar entry point. Determine why insertBefore receives a non-Node and verify that the tool-bar package activates successfully without this TypeError.

Written by the indexing model from the issue text.