Vue v-model incompatible with Bootstrap 3 radio button group

[msmolens]

Binding data to radio inputs using Vue's v-model [1] is incompatible when the inputs are styled as a Bootstrap 3 radio button group [2].

This can be observed for the following radio button group in the annotation tool:

isic-archive/web_external/vue/components/AnnotationTool/AnnotationToolFeatures.vue

Line 24 in e7fb1e8

.btn-group(data-toggle='buttons')

If Bootstrap's button.js is included in the script section (import 'bootstrap/js/button';), then the data binding no longer works: the certainty setter is not called when the buttons are toggled.

Note that since the script doesn't currently include button.js, the data-toggle='buttons' attribute has no effect.

[1] https://vuejs.org/v2/guide/forms.html#Radio
[2] https://getbootstrap.com/docs/3.3/javascript/#buttons-checkbox-radio