PLT-3466 E10: Add announcement bar feature (#6509)

* E10 - Add announcement bar feature

* Updates per feedback

* Add component tests and snapshots

* Update snapshots

* Updating color picker UI (#6543)

* Add class to body tag when banner is not dismissable and clean up localstorage items when banner changes

* Fixing links (#6544)

* Updating UI for fixed error bar (#6552)

* Truncating text on fixed banner (#6561)

* Plt 3466 - Error bar link states (#6577)

* Updating error bar hover state

* Updating error bar link states

webapp/package.json

@@ -30,6 +30,7 @@
     "react": "15.5.4",
     "react-addons-pure-render-mixin": "15.5.2",
     "react-bootstrap": "0.31.0",
+    "react-color": "2.11.7",
     "react-custom-scrollbars": "4.1.2",
     "react-dom": "15.5.4",
     "react-intl": "2.3.0",