v2.2.0

• Remove need for consuming app to configure ember-cli-bootstrap addon #87 @ppcano
• Refer to Discord vs. Slack Fixes #85 @sivakumar-kailasam
• updated the blog header component to remove unnecessary complexity #81 @MelSumner
• list component refactor, added contributor invite #80 @MelSumner
• updated the button component and supporting documentation #79 @MelSumner
• Use ember-cli-addon-docs for dummy app #76 @hakilebara