Remove position relative in pui-panel
Remove position relative in pui-panel

- because we are not using position absolute on anything inside the panel, so consumers should have full control over how they want to position panel content.

Signed-off-by: Kenny Wang <90acc2c8666838f0b9d2271759853d56cb5f2193@pivotal.io>

pivotal-cf/pivotal-ui,pivotal-cf/pivotal-ui,pivotal-cf/pivotal-ui