remove rc-slider dep

Author: KoolADE85

components/dash-core-components/package-lock.json

@@ -53,7 +53,6 @@
     "node-polyfill-webpack-plugin": "^2.0.1",
     "prop-types": "^15.8.1",
     "ramda": "^0.30.1",
-    "rc-slider": "^9.7.5",
     "react-addons-shallow-compare": "^15.6.3",
     "react-dates": "^21.8.0",
     "react-docgen": "^5.4.3",