v1.2.1 Bug Fix and PR Template

FIXED:

• Fixed reference error within render() method (#84 by theopolisme)

NEW:

• New Pull Request template (#82, via #83 by hydrosquall)

Bug Fixes and Dependency Updates

FIXED:

• CDN versions of files now served properly with UTF-8 encoding (#76)
• Fixed typo in sortIntervals() accessor (#66)
• C3 animation property is now editable (#77)

NEW:

• Updated C3.js to v0.4.18, D3.js to v3.5.17 (#74)
• Document use of axis.x.localtime property in C3.js (#78)