treemap sort

- obey npm lint
- add sort option to treemap (define attribute & coerce in default

Treepad is using the calc from sunburst, so the 1 line code change for  sunburst impacted treemap (sort was not true)

Author: thierryVergult

src/traces/sunburst/calc.js

@@ -192,7 +192,7 @@ exports.calc = function(gd, trace) {
     if(failed) return;
 
     // TODO add way to sort by height also?
-    if (trace.sort) {
+    if(trace.sort) {
         hierarchy.sort(function(a, b) { return b.value - a.value; });
     }
 

src/traces/treemap/attributes.js

@@ -268,6 +268,7 @@ module.exports = {
             'Sets the positions of the `text` elements.'
         ].join(' ')
     },
+    sort: pieAttrs.sort,
 
     domain: domainAttrs({name: 'treemap', trace: true, editType: 'calc'}),
 };

src/traces/treemap/defaults.js

@@ -114,6 +114,8 @@ module.exports = function supplyDefaults(traceIn, traceOut, defaultColor, layout
         coerce('pathbar.edgeshape');
     }
 
+    coerce('sort');
+
     handleDomainDefaults(traceOut, layout, coerce);
 
     // do not support transforms for now