Upgrade to d3v4

chorddiag 0.1.3

• Added a NEWS.md file to track changes to the package.
• Finally upgraded d3 to version 4, v4.13.0 to be specific.
• Upgraded d3-tip to version 0.8.1.
• Removed some obsolete external data reducing the package size considerably.

v0.1.2

Added clickAction functionality to chords and groups for better interactivity...

v0.1.0

Bumped up version number to better allow for fixes and minor updates...

Let's call it a relase

v0.0.1

Let's call it a release...