Let me onSkip-it

Features:

• Ember 3.1 upgrade
• New intro on-skip callback support

Merged pull requests:

• Make tests green again #91 (mikoscz)
• Update ember-cli-babel to the latest version 🚀 #90 (greenkeeper[bot])
• Update ember-cli-babel to the latest version 🚀 #88 (greenkeeper[bot])
• Update sinon-chai to the latest version 🚀 #87 (greenkeeper[bot])
• Update ember-cli-dependency-checker to the latest version 🚀 #86 (greenkeeper[bot])
• Update loader.js to the latest version 🚀 #77 (greenkeeper[bot])
• Update ember-cli to the latest version 🚀 #76 (greenkeeper[bot])