Allow for multiple color schemes (#3295)

* Allow for multiple color schemes

1. create ColorSchemeControl component
2. using the same new control component for linear colors

* add color spectum for linear color scheme

* remove dup css

* fix controls setting for linear color scheme

* minor fix by code review comment

superset/assets/spec/javascripts/modules/colors_spec.jsx

@@ -0,0 +1,22 @@
+import { it, describe } from 'mocha';
+import { expect } from 'chai';
+
+import { ALL_COLOR_SCHEMES, getColorFromScheme } from '../../../javascripts/modules/colors';
+
+describe('colors', () => {
+  it('default to bnbColors', () => {
+    const color1 = getColorFromScheme('CA');
+    expect(color1).to.equal(ALL_COLOR_SCHEMES.bnbColors[0]);
+  });
+  it('series with same scheme should have the same color', () => {
+    const color1 = getColorFromScheme('CA', 'bnbColors');
+    const color2 = getColorFromScheme('CA', 'googleCategory20c');
+    const color3 = getColorFromScheme('CA', 'bnbColors');
+    const color4 = getColorFromScheme('NY', 'bnbColors');
+
+    expect(color1).to.equal(ALL_COLOR_SCHEMES.bnbColors[0]);
+    expect(color2).to.equal(ALL_COLOR_SCHEMES.googleCategory20c[0]);
+    expect(color1).to.equal(color3);
+    expect(color4).to.equal(ALL_COLOR_SCHEMES.bnbColors[1]);
+  });
+});