Move ColorPicker leftovers to @grafana/ui

packages/grafana-ui/src/components/ColorPicker/SpectrumPicker.tsx

 import React from 'react';
 import _ from 'lodash';
 import $ from 'jquery';
-import 'vendor/spectrum';
+import '../../vendor/spectrum';
 
 export interface Props {
   color: string;

packages/grafana-ui/src/components/index.scss

@@ -5,3 +5,5 @@
 @import 'Select/Select';
 @import 'PanelOptionsGroup/PanelOptionsGroup';
 @import 'PanelOptionsGrid/PanelOptionsGrid';
+@import 'PanelOptionsGrid/PanelOptionsGrid';
+@import 'ColorPicker/ColorPicker';

packages/grafana-ui/src/index.scss

+@import 'vendor/spectrum';
 @import 'components/index';
+

public/sass/_grafana.scss

@@ -3,7 +3,6 @@
 
 // VENDOR
 @import '../vendor/css/timepicker.css';
-@import '../vendor/css/spectrum.css';
 @import '../vendor/css/rc-cascader.scss';
 
 // MIXINS
@@ -76,7 +75,6 @@
 @import 'components/typeahead';
 @import 'components/modals';
 @import 'components/dropdown';
-@import 'components/color_picker';
 @import 'components/footer';
 @import 'components/infobox';
 @import 'components/shortcuts';