rename boxes / Boxes --> box / Box consistently with trace type

Author: etpinard

src/plotly.js

@@ -58,7 +58,7 @@ exports.ModeBar = require('./components/modebar');
 // traces
 exports.Scatter = require('./traces/scatter');
 exports.Bar = require('./traces/bar');
-exports.Boxes = require('./traces/boxes');
+exports.Box = require('./traces/box');
 exports.Heatmap = require('./traces/heatmap');
 exports.Histogram = require('./traces/histogram');
 exports.Histogram2d = require('./traces/histogram2d');

src/traces/boxes/attributes.js renamed to src/traces/box/attributes.js

@@ -1,4 +1,4 @@
-var Plotly = require('@src/plotly');
+var Box = require('@src/traces/box');
 
 describe('Test boxes', function () {
     'use strict';
@@ -9,7 +9,7 @@ describe('Test boxes', function () {
 
         var defaultColor = '#444';
 
-        var supplyDefaults = Plotly.Boxes.supplyDefaults;
+        var supplyDefaults = Box.supplyDefaults;
 
         beforeEach(function() {
             traceOut = {};