Ensure that medium-editor-insert-plugin honours the buttonLabels setting on medium-editor, when it is set to an object with specific overrides for each button
Merge upstream changes
Merge branch 'support-buttonLabels' of https://github.com/Zeald/medium-editor-insert-plugin into Zeald-support-buttonLabels

Conflicts:
	dist/js/medium-editor-insert-plugin.all.min.js
Merge branch 'Zeald-support-buttonLabels'