Add Tag plugin link for 'Jekyll Twitter Plugin'; A Liquid tag plugin that renders Tweets from Twitter API.
Update normalize.css to v3.0.2.
Merge pull request #2979 from rob-murray/add-twitter-tag-plugin
Update history to reflect merge of #2979 [ci skip]
Update continuous-integration.md

Fix minor typo
Fix site:update_normalize_css so it works with new integrated Sass workflow. [ci skip]

Ref: #2981
Merge pull request #2981 from XhmikosR/normalize
Update history to reflect merge of #2981 [ci skip]
Merge pull request #2984 from kevgathuku/patch-1
Update history to reflect merge of #2984 [ci skip]