Fixed data binding bug

Fixed a bug that did not trigger text refitting when text value was changed via data binding.
Added an interactive demo to showcase the working situation.

V1.0.0 - Polymer hybrid element

-) Polymer hybrid mode implemented - Element can be used in Polymer 1.x and Polymer 2.x now
-) Added CSS mixin for easier styling
-) Updated README.MD demo
-) Do not call textfit when no width or height is set

Switch to iron-flex-layout classes

Merge pull request #3 from xliiv/update-depecations

Switch to new way of using iron-flex-layout classes

Initial release

0.1.0

Updated README.MD