Remove colorbar require in plot_api

Author: hy9be

src/plot_api/plot_api.js

@@ -25,7 +25,6 @@ var Polar = require('../plots/polar');
 
 var Drawing = require('../components/drawing');
 var ErrorBars = require('../components/errorbars');
-var Colorbar = require('../components/colorbar');
 var xmlnsNamespaces = require('../constants/xmlns_namespaces');
 var svgTextUtils = require('../lib/svg_text_utils');