use --name in partial bundle script

Author: archmoj

README.md

@@ -97,7 +97,7 @@ var Plotly = require('./path/to/custom-plotly');
 ```
 
 Alternatively you could browserify a custom bundle of desired trace modules e.g. `pie` and `choropleth` using
-`npm run partial-bundle pie choropleth name=custom`
+`npm run partial-bundle pie choropleth --name=custom`
 
 
 ## Building plotly.js

tasks/partial_bundle.js

@@ -26,7 +26,7 @@ if(argv.length > 2) {
         ) {
             traceList.push(a);
         }
-        if(a.indexOf('name=') !== -1) name = a.replace('name=', '');
+        if(a.indexOf('--name=') === 0) name = a.replace('--name=', '');
     }
     if(!name) name = 'custom';
     traceList = traceList.sort();