Changes to support visualizing arrays of dates in a timeline.

[coderocket]

Hi,

I've changed a few places so that it is now possible to create timelines directly from date objects.

Cheers, David

[bergel]

Hi! This looks like a great contribution. Would you mind to provide

• an example of it (you can simply put it on GitHub, as a comment, I will insert it in the mainstream)
• a unit test that covers your changes This would significantly help us to review your pull request :-)

[bergel]

Travis has spoken. Your change breaks some tests: https://travis-ci.org/ObjectProfile/Roassal2/builds/497465893

[coderocket]

I've added an example to the readme page in my fork, fixed the problem that caused the regression tests to fail and added a test case.

Cheers :)