vue-workflow-chart not rendered when used as script in browser
I tried to use it as script in browser using unpkg, but it's not rendering. Just an empty html custom element "workflow-chart"

To Reproduce
Steps to reproduce the behavior:

1. Add reference using unpkg 'https://unpkg.com/vue-workflow-chart@0.4.5/dist/vue-workflow-chart.umd.min.js'
2. Register component globally 'Vue.component('vue-workflow-chart');'
3. Add custom html element
4. Setup data

Expected behavior
States and transitions to be rendered

Desktop (please complete the following information):

• OS: [windows 10 64]
• Browser [e.g. chrome v 80]
• Version [0.4.5]
• Vue Version [2.5]