paper-button currently imports deprecated iron-flex-layout

[Prithvirajbilla]

Description

paper-button currently imports deprecated iron-flex-layout.html which throws a warning. https://github.com/PolymerElements/paper-button/blob/master/paper-button.html#L12 we should import iron-flex-layout/iron-flex-layout-classes.html instead. https://github.com/PolymerElements/iron-flex-layout/blob/master/iron-flex-layout-classes.html#L17

warning

This file is deprecated. Please useiron-flex-layout/iron-flex-layout-classes.html, and one of the specific dom-modules instead (anonymous) @ iron-flex-layout.html:14

Happy to submit a PR

Thanks

[Prithvirajbilla]

nvm. I understood this wrong. this is not an issue