add timeline, https://developers.google.com/chart/interactive/docs/gallery/timeline
Merge pull request #64 from ghiculescu/master

Fix: chart loading can fail, and cause the entire page to render as a white screen, when using Turbolinks
use 'time' instead of 'timewithoutdate', tweak Cell constructor
Merge pull request #65 from ghiculescu/timeline

Add interactive Timeline chart
Bump version.
Support generating chart Javascript without <script> tag. This allows JS to be used inside a callback function.
* Pass options through to to_js method.
Merge pull request #69 from k1w1/master

Support generating chart Javascript without <script> tag
Split base_chart#to_js into 3 methods that can be used individually - `to_js`, `load_js`, and `draw_js`.

Rails view helper `render_chart` accepts options with `script_tag` true (by default) or false, and generates JS accordingly.
Fix deprecation errors.
Version bump to 2.3.0.
Fix readme.
Remove support for 1.9.2 and add support for 2.0 and 2.1.1
Update README.markdown

Broken link to the Google Charts docs
Merge pull request #71 from andycroll/patch-1

Update README.markdown